JP2781208B2 - Manufacturing method of water absorbent resin - Google Patents

Manufacturing method of water absorbent resin

Info

Publication number
JP2781208B2
JP2781208B2 JP15660189A JP15660189A JP2781208B2 JP 2781208 B2 JP2781208 B2 JP 2781208B2 JP 15660189 A JP15660189 A JP 15660189A JP 15660189 A JP15660189 A JP 15660189A JP 2781208 B2 JP2781208 B2 JP 2781208B2
Authority
JP
Japan
Prior art keywords
water
polymerization
weight
gas phase
monomer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP15660189A
Other languages
Japanese (ja)
Other versions
JPH02138306A (en
Inventor
修平 矢田
毅 芝野
喜一 伊藤
憲司 吉永
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Chemical Corp
Original Assignee
Mitsubishi Chemical Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=27473276&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=JP2781208(B2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Mitsubishi Chemical Corp filed Critical Mitsubishi Chemical Corp
Priority to JP15660189A priority Critical patent/JP2781208B2/en
Priority to EP19890306270 priority patent/EP0348180A3/en
Priority to KR1019890008652A priority patent/KR970009231B1/en
Publication of JPH02138306A publication Critical patent/JPH02138306A/en
Application granted granted Critical
Publication of JP2781208B2 publication Critical patent/JP2781208B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Landscapes

  • Polymerisation Methods In General (AREA)

Description

【発明の詳細な説明】 〔発明の背景〕 （産業上の利用分野） 本発明は、水溶性エチレン性不飽和モノマーを重合し
て得られる吸水性樹脂を製造するにあたり水溶性エチレ
ン性不飽和モノマーを主成分とする溶液を気相中に供給
し、該気相中で重合させる方法に関する。The present invention relates to a water-soluble ethylenically unsaturated monomer for producing a water-absorbent resin obtained by polymerizing a water-soluble ethylenically unsaturated monomer. The present invention relates to a method of supplying a solution containing as a main component into a gas phase and polymerizing in the gas phase.

本発明の一面によれば、水溶性エチレン性不飽和モノ
マーを重合して得られる吸水性樹脂を製造するにあた
り、水溶性エチレン性不飽和モノマーを主成分とする溶
液を水蒸気又は水蒸気と少なくとも一種の重合に実質的
に不活性性を示す気体を混合してなる気相中に供給し、
該気相中で重合させることを特徴とする吸水性樹脂の製
造法が提供される。According to one aspect of the present invention, in producing a water-absorbent resin obtained by polymerizing a water-soluble ethylenically unsaturated monomer, a solution containing a water-soluble ethylenically unsaturated monomer as a main component is steam or at least one of steam and water. Feeding into a gas phase consisting of a mixture of gases which are substantially inert to the polymerization,
There is provided a method for producing a water-absorbent resin, which comprises polymerizing in the gas phase.

更に、本発明の他の面によれば、水溶性エチレン性不
飽和モノマーを主成分とする溶液を上記気相中で重合さ
せて吸水性樹脂を製造するにあたり、重合器内壁温度を
気相温度より高く設定することを特徴とする吸水性樹脂
の製造法が提供される。Furthermore, according to another aspect of the present invention, in producing a water-absorbent resin by polymerizing a solution containing a water-soluble ethylenically unsaturated monomer as a main component in the gas phase, the temperature of the inner wall of the polymerization vessel is raised to the gas phase temperature. There is provided a method for producing a water-absorbent resin, wherein the method is set higher.

吸水性樹脂は、近年、生理用品、おむつ、使い捨て雑
巾などの衛生関係、保水剤、土壌改良剤として農園芸関
係などに使われているほか、汚泥の凝固、結露防止や油
類の脱水などの種々の用途にもまた使用方法が開発され
ている。In recent years, water-absorbent resins have been used in sanitary products such as sanitary products, diapers, disposable rags, water retention agents, soil improvement agents, etc., as well as in agricultural and horticultural applications. Methods of use have also been developed for various applications.

これらの中でも、特に生理用品、おむつ、などの衛生
用品に吸水性樹脂が盛んに使用されているし、結露防止
としては、建材、コンテナー輸送、海上輸送などに利用
され、社会生活に大きく貢献している。Of these, water-absorbent resins are actively used, especially for sanitary products such as sanitary products and diapers, and they are used in building materials, container transportation, marine transportation, etc. to prevent dew condensation, greatly contributing to social life. ing.

（従来の技術） この種の水溶性エチレン性不飽和モノマーを重合して
得られる吸水性樹脂としては、アクリル酸塩重合体架橋
物、アクリル酸エステル−酢酸ビニル共重合体架橋物の
ケン化物、澱粉−アクリル酸塩グラフト共重合体架橋
物、澱粉−アクリロニトリルグラフト共重合体架橋物の
ケン化物、無水マレイン酸グラフトポリビニルアルコー
ル重合体架橋物、ポリエチレンオキシド架橋物などが知
られている。例えば、特公昭60−25045号、特開昭57−1
58210号、特開昭57−21405号、特公昭53−46199号、特
開昭58−71907号、特開昭55−84304号各公報などにその
詳細が示されているが、代表的な製造例としては、次の
ようなものが掲げられる。(Prior art) As a water-absorbing resin obtained by polymerizing this kind of water-soluble ethylenically unsaturated monomer, a crosslinked product of an acrylate polymer, a saponified product of a crosslinked product of an acrylate-vinyl acetate copolymer, Crosslinked starch-acrylate graft copolymers, saponified starch-acrylonitrile graft copolymer crosslinked products, maleic anhydride grafted polyvinyl alcohol polymer crosslinked products, polyethylene oxide crosslinked products, and the like are known. For example, Japanese Patent Publication No. Sho 60-25045,
No. 58210, JP-A-57-21405, JP-B-53-46199, JP-A-58-71907, JP-A-55-84304, etc. Examples include the following:

例−１ α、β−不飽和カルボン酸及びそのアルカリ
金属塩水溶液を架橋剤の存在下または不存在下にショ糖
脂肪酸エステルを含有する石油系炭化水素溶媒中に懸濁
させ、ラジカル重合開始剤の存在下に重合させる方法。Example 1 A radical polymerization initiator in which an aqueous solution of an α, β-unsaturated carboxylic acid and an alkali metal salt thereof is suspended in a petroleum hydrocarbon solvent containing a sucrose fatty acid ester in the presence or absence of a crosslinking agent. Polymerization in the presence of

例−２ アクリル酸及びアクリル酸アルカリ塩水溶液
をHLB8〜12の界面活性剤を共有する脂環族または脂肪族
炭化水素溶媒中に懸濁させ、水溶性ラジカル重合開始剤
の存在下に重合させる方法。Example 2 A method of suspending an aqueous solution of acrylic acid and an alkali acrylic acid salt in an alicyclic or aliphatic hydrocarbon solvent sharing a surfactant of HLB 8 to 12, and polymerizing in the presence of a water-soluble radical polymerization initiator. .

例−３ デンプン及びセルロースのうち少なくとも１
種（Ａ）と付加重合性二重結合を有する水溶性の、また
は加水分解により、水溶性となる単量体の少なくとも１
種（Ｂ）を必須成分として重合し、必要により架橋剤
（Ｃ）を添加して重合したり、重合体を加水分解を行い
重合体を得る方法。Example 3 At least one of starch and cellulose
At least one of a water-soluble monomer having a species (A) and an addition-polymerizable double bond, or water-soluble by hydrolysis;
A method in which the seed (B) is polymerized as an essential component, and if necessary, a crosslinking agent (C) is added for polymerization, or the polymer is hydrolyzed to obtain a polymer.

例−４ アクリル酸カリウムと水混和性ないし水溶性
ジビニル系化合物とを含有し、これら単量体の濃度が55
〜80重量％の範囲にある加温水溶液に重合反応開始剤を
添加して、外部加熱を行うことなく重合反応を行わせる
と共に水分を気化させ水膨潤性ポリマーを得る方法。Example 4 It contains potassium acrylate and a water-miscible or water-soluble divinyl compound, and the concentration of these monomers is 55
A method in which a polymerization reaction initiator is added to a heated aqueous solution in the range of up to 80% by weight to carry out a polymerization reaction without external heating and to vaporize water to obtain a water-swellable polymer.

例−５ 分子量750〜10000のモノオレフィン重合体に
１〜20％のα、β−不飽和カルボン酸あるいは、その無
水物をグラフトした反応生成物、またはモノオレフィン
重合体を最終的に酸価が10〜100になるように酸化して
得られる生成物を保護コロイドに用いて、単量体水溶液
を重合不活性で疎水性の液体中に懸濁させて、水溶性ラ
ジカル重合開始剤の存在下に重合させる方法。Example-5 A reaction product obtained by grafting 1 to 20% of an α, β-unsaturated carboxylic acid or its anhydride to a monoolefin polymer having a molecular weight of 750 to 10,000 or a monoolefin polymer having a final acid value of Using a product obtained by oxidizing to 10 to 100 as a protective colloid, suspending an aqueous monomer solution in a polymerization-inactive and hydrophobic liquid, and in the presence of a water-soluble radical polymerization initiator Method for polymerizing.

吸水性樹脂は、一般に逆相懸濁重合、逆相乳化重合、
水溶液重合または有機溶媒中での反応等の方法によっ
て、重合体を合成し製造されている。Water-absorbent resins are generally reversed-phase suspension polymerization, reversed-phase emulsion polymerization,
It is produced by synthesizing a polymer by a method such as aqueous solution polymerization or reaction in an organic solvent.

これら、従来の重合は、塊状状態での重合であった
り、モノマー溶液が液滴状態ではあるが溶剤中に分散し
た状態での重合であるため、種々の問題が生じている。These conventional polymerizations involve various problems because they are polymerizations in a bulk state or polymerizations in which a monomer solution is in a droplet state but is dispersed in a solvent.

例えば、塊状状態での重合は、重合物が非常に大きな
粘性を示すために特殊な重合反応器を必要としたり、反
応器内部に多量の残量物を残したり、あるいはこの残留
物を抑制するために特殊な界面活性剤を添加したりする
必要があった。また、得られた重合物を粉体状の製品に
するための粉砕機が必要となり、このために生じる微粉
末等を造粒、あるいは再粉砕する必要から必ずしも経済
的に優れた重合法と言えなかった。For example, polymerization in a bulk state requires a special polymerization reactor because the polymer exhibits a very large viscosity, leaves a large amount of residue inside the reactor, or suppresses this residue. Therefore, it was necessary to add a special surfactant. In addition, a pulverizer is required to convert the obtained polymer into a powdery product, and it is necessary to granulate or re-pulverize the resulting fine powder or the like. Did not.

一方、モノマー粒液が液滴状態ではあるが溶剤中に分
散した状態での重合は、汎用の槽型反応器を使用でき、
重合物が、粒状となっているため、工業プロセスとして
は取り扱いやすいものであるが、用いる溶剤との分離、
溶剤の回収／精製設備等が必要となりこれもまた経済的
に優れた重合法と言えなかった。On the other hand, for polymerization in which the monomer particle liquid is in a droplet state but dispersed in a solvent, a general-purpose tank-type reactor can be used.
Since the polymer is granular, it is easy to handle as an industrial process, but separation from the solvent used,
Solvent recovery / purification equipment and the like were required, and this could not be said to be an economically excellent polymerization method.

特公昭32−10196号公報には、アクリル酸塩を噴霧法
で重合させ広範囲の分子量を高変化率で得る方法が提案
されている。しかしながら、この方法では過硫酸塩の誘
導期間が長いため単に空気を過熱するのみの条件では温
度上昇により相対湿度が低下し、且つ高温のため供給さ
れたモノマー液滴から水分が選択的に蒸発し、アクリル
酸塩が析出して、モノマー転化率及び重合度が極めて低
く、水溶性のポリマーしか得られない。Japanese Patent Publication No. 32-10196 proposes a method of polymerizing an acrylate by a spray method to obtain a wide range of molecular weights at a high rate of change. However, this method has a long persulfate induction period, so that if only air is heated, the relative humidity decreases due to temperature rise, and water is selectively evaporated from the supplied monomer droplets due to the high temperature. As a result, acrylates are precipitated, the monomer conversion and the degree of polymerization are extremely low, and only water-soluble polymers can be obtained.

また、特開昭49−105889号公報には、アクリル酸塩を
レドックス系開始剤を用いて噴霧重合する方法が提案さ
れている。しかしながら、この方法で得られるものは水
溶性のポリマーであり、本発明のような自己架橋した水
不溶性の吸水性樹脂は得られない。JP-A-49-105889 proposes a method of spray-polymerizing an acrylate using a redox initiator. However, what is obtained by this method is a water-soluble polymer, and a self-crosslinked water-insoluble water-absorbing resin as in the present invention cannot be obtained.

〔発明の概要〕[Summary of the Invention]

要 旨 本発明は、従来技術の欠点を排除して、水溶性エチレ
ン性不飽和モノマーを重合して得られる吸水性樹脂を安
定的に製造する方法を提供しようとするものである。SUMMARY An object of the present invention is to provide a method for stably producing a water-absorbing resin obtained by polymerizing a water-soluble ethylenically unsaturated monomer, while eliminating the disadvantages of the prior art.

即ち、本発明は、水溶性エチレン性不飽和モノマーを
主成分とするモノマー濃度が少なくとも20重量％の溶液
を、水蒸気または水蒸気と他の少なくとも１種の重合に
実質的に不活性性を示す気体との混合物からなる気相を
収容する重合器に供給し、該気相中、気相の相対湿度30
％以上の条件下で重合して吸水性樹脂を製造する方法を
提供するものである。That is, the present invention relates to a method of converting a solution containing a water-soluble ethylenically unsaturated monomer as a main component and having a monomer concentration of at least 20% by weight into steam or steam and at least one other polymer which is substantially inert to polymerization. Is supplied to a polymerization vessel containing a gas phase composed of a mixture of
% Of water-absorbent resin by polymerization under the condition of not less than 0.1%.

また、更に本発明は、かかる気相重合を、その内壁温
度を気相温度より高く設定した重合器を使用して行う吸
水性樹脂の製造法を提供するものである。Further, the present invention provides a method for producing a water-absorbent resin in which such a gas-phase polymerization is carried out using a polymerization vessel whose inner wall temperature is set higher than the gas-phase temperature.

効 果 この種の水溶性エチレン性不飽和モノマーを重合して
得られる吸水性樹脂を、例えば、塊状状態での重合によ
り製造する場合は、特殊な重合反応器を必要としたり、
反応器内部に多量の残留物を残したり、製造工程上、粉
砕、微粉末等を造粒、あるいは再粉砕の必要があった。
一方、モノマー溶液が液滴状態ではあるが溶剤中に分散
した状態での重合により吸水性樹脂を製造する場合に
は、用いる溶剤との分離、溶剤の回収／精製設備等が必
要であった。しかしながら、本発明の方法を用いると、
簡単な構造の反応器で粒状の重合物が得られ、しかも溶
剤を用いないので、従来の重合法の問題の解決に大きく
貢献するものと言えよう。また、本発明によれば、水溶
性エチレン性不飽和モノマーの重合を水蒸気、又はそれ
と重合に実質的に不活性性を示す気体との混合気相中で
行うことにより、該モノマーの重合を短時間で行うこと
ができる。更に、本発明において、重合器の内壁温度を
重合器内の気相温度より高く設定することによって、重
合器内壁に重合物の付着物が蓄積しにくくなり、また、
蓄積があったとしてもそれは簡単に除去することができ
る。EffectWhen a water-absorbing resin obtained by polymerizing this type of water-soluble ethylenically unsaturated monomer is produced, for example, by polymerization in a bulk state, a special polymerization reactor is required,
A large amount of residue was left inside the reactor, and pulverization, granulation of fine powder or the like had to be performed or re-pulverized in the production process.
On the other hand, when a water-absorbing resin is produced by polymerization in a state where the monomer solution is in the form of droplets but dispersed in a solvent, separation from the solvent to be used and equipment for recovering / purifying the solvent are required. However, using the method of the present invention,
Since a granular polymer can be obtained in a reactor having a simple structure and no solvent is used, it can be said that it greatly contributes to solving the problems of the conventional polymerization method. According to the present invention, the polymerization of the water-soluble ethylenically unsaturated monomer is shortened by performing the polymerization of the monomer in steam or a mixed gas phase thereof with a gas that is substantially inert to the polymerization. Can be done in time. Further, in the present invention, by setting the inner wall temperature of the polymerization vessel higher than the gas phase temperature in the polymerization vessel, it becomes difficult for polymer deposits to accumulate on the polymerization vessel inner wall,
Any build-up can be easily removed.

本発明により、経済的プロセスが構成でき、安価で安
定した品質を得ることが可能となるため、工業的貢献度
は極めて高いものである。According to the present invention, an economic process can be configured, and inexpensive and stable quality can be obtained. Therefore, the industrial contribution is extremely high.

〔発明の具体的な説明〕[Specific description of the invention]

（水溶性エチレン性不飽和モノマー） 本発明に使用される水溶性エチレン性不飽和モノマー
としては、高吸水性樹脂に転換可能で、重合、乾燥等の
後に良好な吸水性能を与えるものであれば何れでもよ
い。(Water-soluble ethylenically unsaturated monomer) As the water-soluble ethylenically unsaturated monomer used in the present invention, any one that can be converted into a superabsorbent resin and gives good water absorption performance after polymerization, drying, etc. Either may be used.

そのような性能を与える水溶性モノマーとしては、官
能基としてカルボン酸または（及び）その塩、リン酸ま
たは（及び）その塩、スルホン酸または（及び）その塩
から誘導される基を有する水溶性エチレン性不飽和モノ
マーが挙げられる。具体的には（メタ）アクリル酸ある
いはその塩、マレイン酸あるいはその塩、イタコン酸あ
るいはその塩、ビニルスルホン酸あるいはその塩、２−
アクリルアミド−２−メチルプロパンスルホン酸あるい
はその塩、２−アクリロイルエタンスルホン酸あるいは
その塩、２−アクリロイルプロパンスルホン酸あるいは
その塩、２−メタクロイルエタンスルホン酸あるいはそ
の塩、ビニルホスホン酸あるいはその塩等を例示でき、
これらの１種または２種以上から構成される。なお、こ
こで「（メタ）アクリル」という用語は、「アクリル」
および「メタクリル」の何れをも意味するものとする。
このうち特に好ましいのはアクリル酸あるいは（及び）
その塩である。この場合そのカルボキシル基の少なくと
も20％が、水酸化ナトリウム、水酸化カリウム、水酸化
アンモニウム等により、アルカリ金属塩またはアンモニ
ウム塩に中和されてなるものである。この部分中和度が
20％未満であるとポリマーの吸水能が著しく低下する。Examples of the water-soluble monomer giving such performance include a water-soluble monomer having a group derived from a carboxylic acid or (and) a salt thereof, phosphoric acid or (and) a salt thereof, sulfonic acid or (and) a salt thereof as a functional group. Ethylenically unsaturated monomers are included. Specifically, (meth) acrylic acid or a salt thereof, maleic acid or a salt thereof, itaconic acid or a salt thereof, vinylsulfonic acid or a salt thereof, 2-
Acrylamide-2-methylpropanesulfonic acid or its salt, 2-acryloylethanesulfonic acid or its salt, 2-acryloylpropanesulfonic acid or its salt, 2-methacryloylethanesulfonic acid or its salt, vinylphosphonic acid or its salt, etc. Can be illustrated,
It is composed of one or more of these. Here, the term “(meth) acryl” means “acryl”
And “methacryl”.
Of these, acrylic acid or (and)
The salt. In this case, at least 20% of the carboxyl groups are neutralized by sodium hydroxide, potassium hydroxide, ammonium hydroxide or the like into alkali metal salts or ammonium salts. This partial neutralization degree
If it is less than 20%, the water absorbing ability of the polymer is significantly reduced.

本発明に使用されるアクリル酸の部分中和塩の中、ナ
トリウム塩については、そのカルボキシル基の20％以上
〜95％未満、好ましくは35％以上〜90％未満、より好ま
しくは40％以上〜80％未満がナトリウム塩に中和されて
なるものである。20％未満での中和では部分中和アクリ
ル酸ナトリウムの水溶解性は著しく大きくなるものの、
吸水性能が小さくなり、また95％以上の中和では、水へ
の溶解性が著しく小さく、さらに吸水能に著しい向上効
果が認められないので好ましくない。また、カリウム塩
については、そのカルボキシル基の40％以上、好ましく
は60％以上がカリウム塩に中和されてなるものである。Among the partially neutralized salts of acrylic acid used in the present invention, as for the sodium salt, 20% or more to less than 95% of the carboxyl group, preferably 35% to less than 90%, more preferably 40% or more. Less than 80% is neutralized with sodium salt. If the neutralization is less than 20%, the water solubility of the partially neutralized sodium acrylate will increase significantly,
It is not preferable that the water absorption performance is reduced, and if the neutralization is 95% or more, the solubility in water is extremely low, and no remarkable improvement effect on the water absorption performance is observed. As for the potassium salt, at least 40%, preferably at least 60%, of the carboxyl groups are neutralized by the potassium salt.

また本発明では、前記の水溶性エチレン性不飽和モノ
マー以外にこれらと共重合可能な単量体、例えば（メ
タ）アクリルアミド、２−ヒドロキシエチル（メタ）ア
クリルアミド、（ポリ）エチレングリコールモノ（メ
タ）アクリレート、２−ヒドロキシエチル（メタ）アク
リレート、または低水溶性モノマーではあるがアクリル
酸メチル、アクリル酸エチル等のアクリル酸アルキルエ
ステル類等も生成吸水性樹脂の性能を低下させない範囲
の量で共重合させても差しつかえない。In the present invention, in addition to the water-soluble ethylenically unsaturated monomers, monomers copolymerizable therewith, such as (meth) acrylamide, 2-hydroxyethyl (meth) acrylamide, (poly) ethylene glycol mono (meth) Acrylate, 2-hydroxyethyl (meth) acrylate, or alkyl acrylates such as methyl acrylate and ethyl acrylate, which are low water-soluble monomers, are copolymerized in an amount that does not lower the performance of the resulting water-absorbent resin. You can do it.

更には、これらモノマーに吸水性能向上のため架橋剤
や添加剤を加えることも可能である。架橋剤としては、
前記モノマーと共重合可能な、例えばN,N′−メチレン
ビス（メタ）アクリルアミド、（ポリ）エチレングリコ
ール（メタ）アクリレート類等のジビニル化合物、エチ
レングリコールジグリシジルエーテル、ポリエチレング
リコールジグリシジルエーテル等のポリグリシジルエー
テル、グリセリン、ペンタエリスリトール等のポリオー
ル、及びエチレンジアミン等のポリアミンなどカルボン
酸、リン酸、スルホン酸等の官能基と反応しうる２個以
上の官能基を有する水溶性の化合物等が好適に使用しう
る。このうち特に好ましいのはN,N′−メチレンビス
（メタ）アクリルアミドである。架橋剤の使用量は、モ
ノマーの仕込み量に対して0.001〜1.0重量％、好ましく
は、0.01〜0.5重量％である。架橋剤の使用量が1.0重量
％より多い時は、極度に架橋度が高い重合体が得られる
ために吸水能が著しく低下する。また、0.001重量％よ
り少ない時は、極度に架橋度が低い重合体が得られるた
め、吸水時のポリマーの強度が弱く、実用上使用に耐え
ない物であったり、水溶性ポリマーであったりするた
め、好ましくない。Further, it is also possible to add a crosslinking agent or an additive to these monomers to improve the water absorption performance. As a crosslinking agent,
Divinyl compounds such as N, N'-methylenebis (meth) acrylamide, (poly) ethylene glycol (meth) acrylates, and polyglycidyls such as ethylene glycol diglycidyl ether and polyethylene glycol diglycidyl ether, which can be copolymerized with the monomers described above. Polyols such as ether, glycerin and pentaerythritol, and water-soluble compounds having two or more functional groups capable of reacting with functional groups such as carboxylic acid, phosphoric acid and sulfonic acid such as polyamine such as ethylenediamine are preferably used. sell. Of these, N, N'-methylenebis (meth) acrylamide is particularly preferred. The amount of the crosslinking agent used is 0.001 to 1.0% by weight, preferably 0.01 to 0.5% by weight, based on the charged amount of the monomer. When the amount of the cross-linking agent is more than 1.0% by weight, a polymer having an extremely high degree of cross-linking is obtained, so that the water absorbing ability is remarkably reduced. On the other hand, when the amount is less than 0.001% by weight, a polymer having an extremely low degree of cross-linking is obtained, so that the strength of the polymer at the time of water absorption is weak, and it may not be practically usable or a water-soluble polymer. Therefore, it is not preferable.

添加剤としては、微粒子状リシカ、二酸化チタン粉
末、及びアルミナ粉末等の不活性な無機質粉末、あるい
は界面活性剤等があって、所望の目的に応じて適時、適
量添加される。Examples of the additive include an inert inorganic powder such as fine particle silica, titanium dioxide powder, and alumina powder, a surfactant, and the like, and are added in an appropriate amount at a time according to a desired purpose.

また、本発明では、上記のような成分から構成される
モノマー水溶液中に分散させてあるいはこのモノマー水
溶液とは別に供給されるものとして、粒〜粒状の吸水性
樹脂用担体を併用することができる。そのような担体と
しては、多孔性ないし吸水性材料たとえばセルロース粉
末、繊維裁断物、スポンジ粉砕物、クレー、セラミック
等の無機物粉末、その他がある。これらの添加剤は、水
溶性モノマー、ひいてはそれから生成する吸水性ポリマ
ー、より多量に使用されることがあるが、そのような場
合であっても、特に添加剤がモノマー溶媒中に存在して
いる場合であっても、重合系をなす気相中に供給するの
は「エチレン性不飽和モノマーを主成分とする溶液」で
あると考えるものとする。Further, in the present invention, a particle-granular water-absorbent resin carrier can be used in combination as being dispersed in an aqueous monomer solution composed of the above components or supplied separately from the aqueous monomer solution. . Examples of such a carrier include porous or water-absorbing materials such as cellulose powder, cut fiber, crushed sponge, inorganic powder such as clay and ceramic, and the like. These additives may be used in larger amounts, as are the water-soluble monomers, and thus the water-absorbing polymer formed therefrom, but even in such cases, the additives are particularly present in the monomer solvent. Even in this case, what is supplied into the gas phase forming the polymerization system is considered to be a “solution containing an ethylenically unsaturated monomer as a main component”.

本発明によれば、「水溶性エチレン性不飽和モノマー
を主成分とする溶液」の溶媒は、水または水と水溶性な
いし水混和性の各種資材との混合物である。後者の水溶
性ないし水混和性の資材としては、水溶性有機溶媒、水
溶性無機塩等があって、それぞれ所期の目的に従って使
用される。また、この溶液は、水溶性重合開始剤（詳細
後記）の溶存したものであってもよい。According to the present invention, the solvent of the "solution containing a water-soluble ethylenically unsaturated monomer as a main component" is water or a mixture of water and various water-soluble or water-miscible materials. The latter water-soluble or water-miscible materials include a water-soluble organic solvent, a water-soluble inorganic salt and the like, each of which is used according to the intended purpose. This solution may be a solution in which a water-soluble polymerization initiator (details described later) is dissolved.

上述の水溶性エチレン性不飽和モノマーを主成分とす
る溶液、すなわち重合原料用モノマー溶液、の水溶性エ
チレン性不飽和モノマーの濃度は、20重量％以上、好ま
しくは25重量％以上、である。濃度が20重量％より少な
いと重合後の吸水性樹脂の吸水能が十分に得られないた
め好ましくない。上限は80重量％程度である。The concentration of the water-soluble ethylenically unsaturated monomer in the solution containing the above-mentioned water-soluble ethylenically unsaturated monomer as a main component, that is, the monomer solution for a polymerization raw material, is 20% by weight or more, preferably 25% by weight or more. If the concentration is less than 20% by weight, it is not preferable because the water absorbing ability of the water absorbent resin after polymerization cannot be sufficiently obtained. The upper limit is about 80% by weight.

また、上記のアクリル酸の部分中和塩の水溶液中での
濃度は、中和度によって変化するが、ナトリウム塩の場
合、通常は45〜80重量％、好ましくは55〜70重量％が採
用される。80重量％以上の濃度では部分中和アクリル酸
ナトリウム水溶液の温度を著しく高くするか、あるいは
中和度を小さく、例えば20％以下とする必要がある為に
好ましくない。一方、45重量％以下の濃度では吸水能向
上効果は認められず、かつ、水分濃度が高くなることか
ら後の乾燥処理に負荷がかかって得策ではない。また、
カリウム塩の場合、通常は45〜80重量％、好ましくは55
〜80重量％が採用される。The concentration of the partially neutralized salt of acrylic acid in the aqueous solution varies depending on the degree of neutralization. In the case of a sodium salt, the concentration is usually 45 to 80% by weight, preferably 55 to 70% by weight. You. A concentration of 80% by weight or more is not preferable because the temperature of the aqueous solution of partially neutralized sodium acrylate must be extremely high or the degree of neutralization must be low, for example, 20% or less. On the other hand, at a concentration of 45% by weight or less, no effect of improving the water absorbing ability is recognized, and since the water concentration increases, a load is imposed on the subsequent drying treatment, which is not a good idea. Also,
In the case of potassium salts, usually 45 to 80% by weight, preferably 55
~ 80% by weight is employed.

上記のようなナトリウム塩のアクリル酸の中和には、
ナトリウムの水酸化物や重炭酸塩等が使用可能である
が、特に好ましいものとしては水酸化ナトリウムが挙げ
られる。To neutralize the sodium salt of acrylic acid as described above,
Sodium hydroxide and bicarbonate can be used, but particularly preferred is sodium hydroxide.

重 合 本発明による重合法は、モノマー溶液を気相中で重合
させることからなるものである。従って、そのような重
合が可能で、しかも本発明の特徴に従って重合器内壁温
度を気相重合温度より高く設定することが可能である限
り、合目的的な任意の方法および機器を採用することが
できる。Polymerization The polymerization method according to the present invention comprises polymerizing a monomer solution in a gas phase. Therefore, any suitable method and apparatus can be adopted as long as such polymerization is possible and the temperature of the inner wall of the polymerization vessel can be set higher than the gas phase polymerization temperature according to the features of the present invention. it can.

（重合器） 重合の場である気相を収容して本発明の気相重合を実
施するための重合器は、その内壁温度を所定のレベルに
保つことができるに任意の槽状、管状、その他の形状の
ものでありうる。(Polymerization Unit) The polymerization unit for carrying out the gas phase polymerization of the present invention by accommodating the gas phase, which is a place for the polymerization, has an arbitrary tank shape, tubular shape, It can be of other shapes.

器壁温度を所定レベルに保持するためには、重合器内
気相の外部循環系を設けてそこで加熱ないし冷却を行な
ったり、外部にジャケットを設けて適当な加熱媒体を流
通させたり、電熱によったりすることができる。In order to maintain the vessel wall temperature at a predetermined level, an external circulation system for the gas phase in the polymerization vessel is provided to perform heating or cooling there, or a jacket is provided outside to allow a suitable heating medium to flow, or by electric heating. Or you can.

重合器内は、ポリマーの付着防止あるいは付着物の除
去容易化のためには付設物が何もない事が好ましいが、
器内の気相の流動状態を調節するための適当な付設物た
とえば邪魔板、撹拌翼その他があってもよい。In the polymerization vessel, it is preferable that there is nothing attached to prevent adhesion of the polymer or facilitate removal of the adhesion,
There may be suitable accessories for adjusting the flow state of the gas phase in the vessel, such as baffles, stirring blades and the like.

重合器内にモノマー水溶液等を供給する少なくとも１
個所の供給口を設けることが必要であり、また生成ポリ
マー粉末を排出するための回分式または連続式排出口を
設けることが必要である。生成ポリマー粉末の排出は、
気相の一部と共に流動状態で行なうことも可能である。At least one for supplying an aqueous monomer solution or the like into the polymerization vessel
It is necessary to provide a point of supply and to provide a batch or continuous outlet for discharging the produced polymer powder. The discharge of the produced polymer powder
It is also possible to work in a fluid state with a part of the gas phase.

添付の第１〜３図は、本発明で使用するのに適当な装
置の具体例を示すものである。図示のものは原理を示す
にとどまるものであって、本発明の趣旨を損なわない限
りは付帯設備の追加は本発明の範疇に入るものである。The accompanying FIGS. 1-3 show embodiments of devices suitable for use in the present invention. The illustrated ones merely show the principle, and the addition of additional equipment falls within the scope of the present invention unless the purpose of the present invention is impaired.

第１図は、化学的重合開始財を利用して重合開始を行
う場合の重合装置の１例である。第２図は、UV照射及び
／あるいは高エネルギー放射線を利用して重合開始を行
う場合の重合装置の１例である。なお、この装置を使用
する場合に、化学的重合開始剤を併用することもでき
る。FIG. 1 is an example of a polymerization apparatus in which polymerization is initiated using a chemical polymerization initiator. FIG. 2 is an example of a polymerization apparatus in which polymerization is initiated using UV irradiation and / or high-energy radiation. When using this apparatus, a chemical polymerization initiator can be used in combination.

第３図は、第１図の装置構成に乾燥設備を付帯させた
ものである。この付帯設備は第２図の装置構成にも付帯
できることは明白である。FIG. 3 shows a configuration in which a drying facility is added to the apparatus configuration of FIG. Obviously, this additional equipment can be added to the apparatus configuration shown in FIG.

第４図は、第１図の装置構成において、気流の流れを
モノマー液滴供給方法と向流接触させた装置を示すもの
である。いずれの装置においても、図中の記号について
は後記の図面の簡単な説明を参照されたい。FIG. 4 shows an apparatus in which the flow of the air stream is brought into countercurrent contact with the monomer droplet supply method in the apparatus configuration of FIG. In any of the devices, refer to the brief description of the drawings for symbols in the drawings.

（重合器へのモノマー溶液の供給および重合開始） 水溶性エチレン性不飽和モノマーを主成分とする溶液
は、上記のような重合器内の気相中に、好ましくは均一
に分散させて、１個所または数個所の供給口から供給さ
れる。供給方法には特に限定はないが、均一分散の観点
からはアトマイザー又はスプレーによる噴霧供給が適当
である。供給方向は、重力方向、反重力方向、水平方向
たとえば重合器求心方向あるいは切線方向、その他でよ
いが、反重力方向への供給が好ましい。(Supply of Monomer Solution to Polymerization Unit and Initiation of Polymerization) A solution containing a water-soluble ethylenically unsaturated monomer as a main component is preferably uniformly dispersed in a gas phase in the polymerization unit as described above to obtain a solution. It is supplied from one or several supply ports. The supply method is not particularly limited, but spray supply using an atomizer or a spray is suitable from the viewpoint of uniform dispersion. The supply direction may be a gravity direction, an antigravity direction, a horizontal direction such as a polymerization vessel centripetal direction or a cut line direction, and the like, but the supply in the antigravity direction is preferable.

供給すべきモノマー溶液の温度は、常温でも、また温
度制御上から常温より高くてもあるいは低くてもよい。The temperature of the monomer solution to be supplied may be room temperature, or may be higher or lower than room temperature from the viewpoint of temperature control.

供給後の重合開始は、水溶性エチレン性不飽和モノマ
ー溶液に重合開始剤を予めあるいは重合器内でたとえば
モノマー水溶液とは別の供給口から供給して混合し、必
要ならば加熱等の処理を用いたり、あるいは、増感剤を
混合した該溶液を供給後に紫外線照射したり、あるい
は、該溶液を供給後に高エネルギー放射線を照射したり
して行われる。After the supply, the polymerization is started by mixing the polymerization initiator with the water-soluble ethylenically unsaturated monomer solution in advance or in a polymerization vessel, for example, by supplying the monomer aqueous solution from a different supply port from the monomer aqueous solution, and if necessary, heating or the like. UV irradiation is performed after supplying the solution containing the sensitizer, or irradiation with high energy radiation is performed after supplying the solution.

すなわち、本発明でモノマーを重合させる方法の典型
的なものとしては、水溶性ラジカル重合開始剤によるも
の、紫外線あるいは高エネルギー放射線の照射によるも
の等があり、これらの１種、あるいは２種以上の方法を
用いることができる。That is, typical methods of polymerizing monomers in the present invention include those using a water-soluble radical polymerization initiator, those using irradiation of ultraviolet rays or high-energy radiation, and the like. A method can be used.

本発明で使用する水溶性ラジカル開始剤は、高分子化
学の分野において周知のものである。具体的には、無機
または有機過酸化物例えば過硫酸塩（アンモニウム塩、
アルカリ金属塩（特にカリウム塩、その他）、過酸化水
素、ジ第三ブチルペルオキシド、アセチルペルオキシ
ド、その他、がある。これらの酸化物の他に、所定の水
溶性が得られるならば、アゾ化合物その他のラジカル重
合開始剤、例えば2,2′−アゾビス（２−アミノジプロ
パン）二塩酸塩、も使用可能である。The water-soluble radical initiator used in the present invention is well known in the field of polymer chemistry. Specifically, inorganic or organic peroxides such as persulfates (ammonium salts,
There are alkali metal salts (especially potassium salts and others), hydrogen peroxide, di-tert-butyl peroxide, acetyl peroxide and others. In addition to these oxides, azo compounds and other radical polymerization initiators, for example, 2,2'-azobis (2-aminodipropane) dihydrochloride can be used as long as a predetermined water solubility is obtained. .

重合は、これらのラジカル重合開始剤の分解によって
開始されるわけであるが、分解のための慣用手段である
加熱（モノマーと接触したときの温度がすでに分解温度
である場合が多く、特に加熱をしなくても重合開始剤を
モノマーに添加するだけで重合が開始される場合をこの
明細書では加熱による分解の範疇に入るものとする）の
外に、化学物質によって重合開始剤の分解を促進するこ
ともまた周知の手段である。重合開始剤が過酸化物であ
るときのその分解促進物質は還元性化合物（本発明では
水溶性のもの）例えば過硫酸塩に対しては酸性亜硫酸
塩、アスコルビン酸、アミン等であって、過酸化物と還
元性化合物との組合わせからなる重合開始剤は、「レド
ックス開始剤」として高分子化学の分野で周知のもので
ある。従って、本発明で「重合開始剤」という用語は、
この様な分解促進物質との組み合わせ、特にレドックス
開始剤、を包含するものである。Polymerization is initiated by the decomposition of these radical polymerization initiators. However, heating, which is a conventional means for decomposition (in many cases, the temperature at the time of contact with the monomer is already the decomposition temperature, especially heating In this specification, the case where the polymerization is initiated only by adding the polymerization initiator to the monomer without the addition of the polymerization initiator is included in the category of decomposition by heating.) In addition, the decomposition of the polymerization initiator is promoted by a chemical substance. Doing is also a well-known means. When the polymerization initiator is a peroxide, its decomposition promoting substance is a reducing compound (a water-soluble one in the present invention) such as an acid sulfite, ascorbic acid, or an amine for persulfate. Polymerization initiators composed of a combination of an oxide and a reducing compound are well known in the field of polymer chemistry as "redox initiators". Therefore, in the present invention, the term "polymerization initiator"
The combination with such a decomposition promoting substance, in particular, a redox initiator is included.

上記の様な水溶性ラジカル重合開始剤の使用量は、水
溶性エチレン性不飽和モノマーに対して一般的には0.00
1〜10重量％、好ましくは0.1〜５重量％、である。The amount of the water-soluble radical polymerization initiator as described above is generally 0.001 to the water-soluble ethylenically unsaturated monomer.
It is 1 to 10% by weight, preferably 0.1 to 5% by weight.

高エネルギー放射線としては、電磁放射線や微粒子イ
オン放射線等がある。紫外線照射による場合は、増感剤
を使用することがしばしば行なわれる。Examples of high-energy radiation include electromagnetic radiation and particulate ion radiation. In the case of ultraviolet irradiation, a sensitizer is often used.

（気相条件） 上述の水溶性エチレン性不飽和モノマーの溶液を重合
させる場を与える気相を構成する気体の種類は、重合に
実質的に不活性性を示す気体であればいずれでもよい。
具体的には、たとえば、水蒸気、空気、窒素、アルゴ
ン、ヘリウム、ネオン等から選ばれた１種または２種以
上が使用でき、工業的に好適なものとしては、空気及び
／又は窒素と水蒸気との混合物、或いは水蒸気のみが好
ましい。気相の相対湿度は、一般的には30％以上、好ま
しくは60％以上である。相対湿度が30％未満であると、
供給されたモノマー水溶液の液滴径が10μφ未満の場
合、重合開始前にモノマー液滴から水分が蒸発し、固形
分が析出し、未反応モノマー分として残留したり、全く
反応が開始されなくなる場合もあるので好ましくない。(Gas Phase Conditions) The kind of gas constituting the gas phase which provides a place for polymerizing the solution of the above-mentioned water-soluble ethylenically unsaturated monomer may be any gas which is substantially inert to the polymerization.
Specifically, for example, one or more selected from steam, air, nitrogen, argon, helium, neon, and the like can be used, and industrially suitable materials include air and / or nitrogen and steam. Or only steam. The relative humidity of the gas phase is generally at least 30%, preferably at least 60%. If the relative humidity is less than 30%,
When the droplet diameter of the supplied monomer aqueous solution is less than 10 μφ, water evaporates from the monomer droplets before the start of polymerization, a solid content precipitates out, remains as an unreacted monomer component, or the reaction does not start at all. It is not preferable because there is also.

空気は重合を抑制することがあるが、本発明では重合
に実質的に不活性性を示す気体として扱うこととする。Although air may inhibit polymerization, the present invention treats it as a gas that is substantially inert to polymerization.

気相の温度は、供給されるモノマー水溶液の持ち込む
熱量および重合熱を考慮して、重合が遅滞なく開始され
かつ継続されるのに十分なものであるように設定すべき
である。重合開始後の重合温度でいえば、これを使用す
る重合開始方法及び／あるいは重合速度に相関するもの
であるけれども、一般には、10−300℃、好ましくは20
−250℃、より好ましくは20−110℃である。10℃より低
いと重合速度が遅いために空間距離が長くなるので、経
済的な工業プロセスとならない。また、300℃より高い
と、生成ポリマーが自己架橋しやすくなるため架橋密度
が増加し、吸水能が低くなる。The temperature of the gas phase should be set so as to be sufficient for the polymerization to be started and continued without delay, taking into account the amount of heat brought in by the supplied aqueous monomer solution and the heat of polymerization. Generally speaking, the polymerization temperature after the initiation of the polymerization is correlated with the polymerization initiation method and / or the polymerization rate in which it is used, but it is generally 10-300 ° C., preferably 20-300 ° C.
-250 ° C, more preferably 20-110 ° C. If the temperature is lower than 10 ° C., the polymerization rate is low, so that the space distance becomes long, so that it is not an economical industrial process. On the other hand, when the temperature is higher than 300 ° C., the resulting polymer is apt to self-crosslink, so that the crosslinking density increases and the water absorbing ability decreases.

また、水蒸気のみを使用する場合、気相の温度は、一
般には、20−300℃、好ましくは105−230℃、である。2
0℃より低いと重合速度が遅いために滞留時間が長くな
るので、経済的な工業プロセスとならない。また、300
℃より高いと、生成ポリマーが自己架橋しやすくなるた
め架橋密度が増加し、吸水能が低くなる。なお、本発明
方法が通常の液相重合では採用され難い200℃以上の高
温でさえも実施できるのは、重合時間が短時間となるの
で生成ポリマーの品温がそれほど上昇してないからであ
ろうと推定される。When only steam is used, the temperature of the gas phase is generally 20-300 ° C, preferably 105-230 ° C. Two
If the temperature is lower than 0 ° C., the polymerization rate is low, so that the residence time becomes long, so that it is not an economical industrial process. Also, 300
When the temperature is higher than ℃, the resulting polymer is apt to self-crosslink, so that the crosslinking density increases and the water absorbing ability decreases. The reason that the method of the present invention can be carried out even at a high temperature of 200 ° C. or higher, which is difficult to be employed in ordinary liquid phase polymerization, is that the polymerization time is short, so that the product temperature of the produced polymer does not rise so much. It is presumed to be.

気相の圧力は特に限定されず、減圧下、常圧下、加圧
下の何れで実施してもよい。The pressure of the gas phase is not particularly limited, and it may be carried out under reduced pressure, normal pressure, or under pressure.

気相を構成する気体の流れは、供給された水溶性エチ
レン性不飽和モノマー溶液の流動方向に対して特に限定
されず、向流流れ、並流流れ、あるいは静止状態の何れ
でもよく、好ましくは、水溶性エチレン性不飽和モノマ
ー溶液の重合時の滞空時間を長くできる反重力方向の流
れがよい。また、流れの状態は、反応器内部で速度分布
を持つことが好ましく、壁面近傍を高速流速で流した
り、壁面から気体を供給することも可能である。流れの
速度は気相流れの平均速度として、20M/秒以下、好まし
くは5M/秒以下、が良い。20M/秒より大きい速度では、
大量の気相流れが必要となって、大型の送風機等が必要
となることから経済的に好ましくない。The flow of the gas constituting the gas phase is not particularly limited with respect to the flow direction of the supplied water-soluble ethylenically unsaturated monomer solution, and may be any of a countercurrent flow, a cocurrent flow, or a stationary state, and is preferably In addition, a flow in the direction of antigravity, which can prolong the time during which the water-soluble ethylenically unsaturated monomer solution is polymerized, is preferable. Also, the flow state preferably has a velocity distribution inside the reactor, and it is possible to flow at a high flow velocity near the wall surface or to supply gas from the wall surface. The flow velocity is preferably 20 M / sec or less, preferably 5 M / sec or less, as an average velocity of the gas phase flow. At speeds greater than 20M / s,
Since a large amount of gas phase flow is required and a large-sized blower is required, it is not economically preferable.

気流中での滞留時間については、気流温度、気流中の
水蒸気分圧、モノマー供給温度等により良好な結果を得
ることができる範囲は異なるが、好ましくは0.01秒〜12
0秒、更に好ましくは0.1秒〜60秒である。0.01秒未満で
あるとモノマーのポリマーへの転化率が低く、かつ架橋
が充分でないため、得られたポリマーの吸水時の形態保
持性が悪い。また、120秒より大きいと重合器のサイズ
が大きくなるため経済的でない。Regarding the residence time in the gas stream, the range in which good results can be obtained varies depending on the gas stream temperature, the partial pressure of water vapor in the gas stream, the monomer supply temperature, and the like, but is preferably 0.01 second to 12 seconds.
0 second, more preferably 0.1 second to 60 seconds. When the time is less than 0.01 second, the conversion of the monomer to the polymer is low, and the crosslinking is not sufficient, so that the obtained polymer has poor shape retention during water absorption. On the other hand, if the time is longer than 120 seconds, the size of the polymerization vessel becomes large, so that it is not economical.

以上の気相条件中で実施される重合は、その大部分を
気相中で進行させることが好ましい。また、この場合
は、回分操作、半回分操作、連続操作の何れによって行
ってもよく、原料モノマー液の重合器供給後の滞空時間
を気流流れの速度で制御すれば何れの方法も簡単に設定
できる。このうち工業的に好ましいのは、連続操作であ
る。重合後の生成ポリマーの収集方法は、静置沈降、サ
イクロン、フィルター等何れでもよく、得られる重合物
の粒子径によって選択すればよい。It is preferable that most of the polymerization carried out under the above-mentioned gas-phase conditions proceed in the gas phase. In this case, the batch operation, the semi-batch operation, or the continuous operation may be performed, and any method can be easily set by controlling the dwell time after the raw material monomer liquid is supplied to the polymerization vessel by the speed of the gas flow. it can. Among them, the industrial operation is preferably a continuous operation. The method of collecting the produced polymer after polymerization may be any of standing sedimentation, a cyclone, and a filter, and may be selected according to the particle size of the obtained polymer.

（反応器壁面温度条件） 反応器壁面での重合物の付着抑制あるいは付着物の除
去を容易にするため、反応器壁面温度は反応器内気相温
度より少なくとも10℃高いこと、好ましくは少なくとも
30℃高いこと、が望ましい。温度差が10℃未満である
と、付着物蓄積量が増大して、長時間の連続運転は困難
となる。また、反応器内壁面温度そのものは少なくとも
20℃であること（300℃以下が好ましい）、好ましくは
少なくとも90℃、更に好ましくは少なくとも130℃、で
あることが望ましい。(Reactor wall surface temperature condition) In order to suppress adhesion of the polymer on the reactor wall surface or to facilitate the removal of the adhered material, the reactor wall surface temperature is at least 10 ° C. higher than the gas phase temperature in the reactor, preferably at least
It is desirable to be 30 ° C. higher. If the temperature difference is less than 10 ° C., the amount of deposits increases and continuous operation for a long time becomes difficult. In addition, at least the inner wall temperature of the reactor
It is desirably 20 ° C. (preferably 300 ° C. or less), preferably at least 90 ° C., and more preferably at least 130 ° C.

反応器壁面状態は、上述の壁面温度条件を実施すれ
ば、重合付着物を抑制、あるいは簡便に除去すれば、更
にこの効果を増大させるため、金属面であればその壁面
平滑戸を増加させたり、樹脂等のコーティングを施すこ
とも本発明の条件下で実施できる。If the wall surface condition of the reactor is carried out under the above-mentioned wall temperature conditions, if polymerized deposits are suppressed or easily removed, this effect is further increased. , A resin or the like can be applied under the conditions of the present invention.

反応器内壁面に付着した重合物を運転中に簡便に除去
する方法としては、例えば、エアーノッカー等の軽度の
衝撃を与える方法、エアースイーパー等による壁面に気
流を与える方法等があり、本発明の条件下での併用で、
更に良好な結果を得ることができる。Examples of the method for easily removing the polymer adhered to the inner wall surface of the reactor during operation include a method of giving a slight impact with an air knocker or the like, a method of giving an air current to the wall surface with an air sweeper or the like, and the present invention. In combination under the conditions of
Even better results can be obtained.

このようにして得られたポリマーからなる吸水性樹脂
は、用途に応じて必要があれば引き続いて該樹脂を乾燥
する工程等を施せばよい。これらの工程は公知の方法を
そのまま適用すればよく、特別の操作、装置を使用する
必要はない。例えば、乾燥装置として熱風乾燥機、赤外
線乾燥機、流動層乾燥機等を使用でき、乾燥温度は通常
70−200℃程度とすれば良い。得られた乾燥吸水性樹脂
は、例えば振動式分級機、風力式分級機等を用いて所望
の粒度に分級することができる。The water-absorbing resin comprising the polymer thus obtained may be subjected to a subsequent step of drying the resin, if necessary, depending on the application. In these steps, a known method may be applied as it is, and there is no need to use a special operation or device. For example, a hot air dryer, an infrared dryer, a fluidized bed dryer, etc. can be used as the drying device, and the drying temperature is usually
The temperature may be about 70-200 ° C. The obtained dried water-absorbent resin can be classified to a desired particle size using, for example, a vibration classifier, a wind classifier, or the like.

上記方法で得られた吸水性樹脂は、必要に応じて後改
質することも可能である。例えば、吸水性樹脂に含有さ
れるカルボキシレートと水溶性ジグリシジルエーテル化
合物、ハロエポキシ化合物、アルデヒド化合物、シアノ
ール化合物等の公知の架橋剤とを反応させて吸水性樹脂
の表面改質をすることも可能である。このような改質物
も吸水性樹脂として前記と同じ用途に利用することがで
きる。The water-absorbing resin obtained by the above method can be post-modified if necessary. For example, it is possible to modify the surface of the water-absorbent resin by reacting a carboxylate contained in the water-absorbent resin with a known crosslinking agent such as a water-soluble diglycidyl ether compound, a haloepoxy compound, an aldehyde compound, and a cyanol compound. It is. Such a modified product can also be used as a water-absorbing resin for the same uses as described above.

〔実験例〕(Experimental example)

以下、実施例、比較例、参考例によって本発明を具体
的に説明するが、本発明がこれらに限定されないことは
もとよりである。Hereinafter, the present invention will be described in detail with reference to Examples, Comparative Examples, and Reference Examples, but it goes without saying that the present invention is not limited to these.

参考例１ 撹拌機およびジャケットを備えたSUS304製の撹拌槽中
に80重量％のアクリル酸水溶液37.5重量部を取り、外部
より冷却しつつ、25.4重量％の苛性ソーダ水溶液49.3重
量部を滴下して75モル％の中和を行った後、N,N′−メ
チレンビスアクリルアミド0.021重量部を加えて溶解し
て、モノマー濃度42.5重量％のアクリル酸部分中和塩水
溶液を原料モノマーとした。Reference Example 1 37.5 parts by weight of an 80% by weight aqueous solution of acrylic acid was placed in a SUS304 stirring tank equipped with a stirrer and a jacket, and 49.3 parts by weight of a 25.4% by weight aqueous solution of caustic soda was added dropwise while cooling from the outside. After neutralization by mol%, 0.021 part by weight of N, N'-methylenebisacrylamide was added and dissolved, and an aqueous solution of partially neutralized acrylic acid having a monomer concentration of 42.5% by weight was used as a raw material monomer.

参考例２ 撹拌機およびジャケットを備えたSUS304製の撹拌槽中
に79.1重量％のアクリル酸水溶液100重量部を取り、外
部より冷却しつつ、48重量％の苛性ソーダ36.6重量部を
滴下して40モル％の中和を行った後、N,N′−メチレン
ビスアクリルアミド0.03重量部を加えて溶解して、モノ
マー濃度65重量％のアクリル酸部分中和塩水溶液を原料
モノマーとした。Reference Example 2 100 parts by weight of a 79.1% by weight aqueous acrylic acid solution was placed in a SUS304 stirring tank equipped with a stirrer and a jacket, and 36.6 parts by weight of 48% by weight caustic soda was added dropwise while cooling from the outside to 40 mol. After neutralization, 0.03 parts by weight of N, N'-methylenebisacrylamide was added and dissolved, and an aqueous solution of partially neutralized acrylic acid having a monomer concentration of 65% by weight was used as a raw material monomer.

参考例３ 撹拌機、ジャケットを備えたSUS306製の撹拌槽中に7
9.1重量％のアクリル酸水溶液90.1重量部を取り、外部
より冷却しつつ、96重量％の苛性カリ40.9重量部を滴下
して75モル％の中和を行った後、N,N′−メチレンビス
アクリルアミド0.024重量部を加えて溶解し、モノマー
濃度74.7重量％のアクリル酸部分中和塩水溶液を原料モ
ノマーとした。Reference Example 3 In a SUS306 stirring tank equipped with a stirrer and jacket, 7
90.1 parts by weight of a 9.1% by weight aqueous solution of acrylic acid was taken, and 40.9 parts by weight of 96% by weight of caustic potassium was added dropwise while cooling from the outside to neutralize 75% by mole, and then N, N'-methylenebisacrylamide was added. 0.024 parts by weight was added and dissolved, and an aqueous solution of partially neutralized acrylic acid having a monomer concentration of 74.7% by weight was used as a raw material monomer.

実施例１ 参考例１の原料モノマー100重量部に開始剤としてＬ
−アスコルビン酸0.75重量部を混合／溶解し、Ａ液とし
た。次に、同じ参考例１の原料モノマー100重量部に開
始剤として濃度31重量％の過酸化水素水2.5重量部を混
合／均一化し、Ｂ液とした。Ａ液とＢ液は、第１図の重
合器（300cmφ×900cm）に供給され、重合された。重合
器の気相流れ条件は、窒素及び水蒸気雰囲気下、重合器
入口の気相温度40℃、気相の相対湿度70％、重合部の気
流平均流速0.9M/秒であった。原料であるＡ液とＢ液の
供給条件は、供給圧力2kg/cm2、供給速度0.1リットル／
分で、供給ラインの先端には供給ノズルとして（株）イ
ケウチ製のLuminaPR−８を設置した。重合は、約１秒後
に、すでに液滴として供給された気相流中で開始し、開
始後約20秒で重合器より系外へ流出させた。原料モノマ
ーの供給、及び得られた重合物の固気分離は、連続的に
実施された。重合物は、乾燥後の純水に対する吸水量が
自重の860倍であるものであり、平均粒径は130μｍ、粒
子形状は擬似球形であった。Example 1 100 parts by weight of the raw material monomer of Reference Example 1
-0.75 parts by weight of ascorbic acid was mixed / dissolved to obtain solution A. Next, 2.5 parts by weight of a hydrogen peroxide solution having a concentration of 31% by weight as an initiator was mixed / homogenized with 100 parts by weight of the raw material monomer of Reference Example 1 to obtain a liquid B. Solution A and Solution B were supplied to the polymerization vessel (300 cm φ × 900 cm) shown in FIG. 1 and polymerized. The gas phase flow conditions of the polymerization vessel were as follows: under nitrogen and steam atmosphere, the gas phase temperature at the polymerization vessel inlet was 40 ° C., the relative humidity of the gas phase was 70%, and the average gas flow velocity in the polymerization section was 0.9 M / sec. The supply conditions of the liquids A and B are as follows: supply pressure 2 kg / cm 2 , supply rate 0.1 liter /
At the end of the supply line, LuminaPR-8 manufactured by Ikeuchi Co., Ltd. was installed as a supply nozzle. The polymerization was started about 1 second later in the gas phase flow already supplied as droplets, and about 20 seconds after the start, the polymer was discharged from the polymerization vessel to the outside of the system. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. The polymer had a water absorption with respect to pure water after drying of 860 times its own weight, an average particle size of 130 μm, and a particle shape of a pseudo spherical shape.

実施例２ 重合器の気相流れ条件を、重合器入口の気相温度60
℃、重合部の気流平均流速1.9M/秒、原料であるＡ液と
Ｂ液の供給条件を、供給圧力2kg/cm2、供給速度0.2リッ
トル／分に変更した以外は実施例１と同一条件で実施し
た。重合物は、乾燥後の純水に対する吸水量が自重の80
0倍であるものであり、平均粒径は290μｍ、粒子形状は
擬似球形であった。Example 2 The gas phase flow conditions of the polymerization reactor were changed to the gas phase temperature of 60 at the polymerization reactor inlet.
The same conditions as in Example 1 except that the supply conditions of the liquid A and the liquid B as the raw materials were changed to 2 kg / cm 2 and the supply rate of 0.2 liter / min. It was carried out in. The polymer has a weight of 80% of its own weight with respect to pure water after drying.
The average particle diameter was 290 μm, and the particle shape was pseudo spherical.

実施例３ 参考例２の原料モノマー100重量部に開始剤としてＬ
−アスコルビン酸0.55重量部を混合／溶解し、Ｃ液とし
た。次に、同じ参考例２の原料モノマー100重量部に開
始剤として濃度31重量％の過酸化水素1.9重量部を混合
／均一化し、Ｄ液とした。Ｃ液とＤ液は第１図の重合器
に供給され、重合された。重合器の条件は、実施例１と
同一条件で実施した。重合は、Ｃ液とＤ液の供給後、約
３秒後に、すでに液滴として供給された気相流中で開始
し、開始後約５秒で終了した。原料モノマーの供給、及
び得られた重合物の固気分離は連続的に実施された。重
合物は、乾燥後の純水に対する吸水量が自重の760倍で
あるものであり、平均粒径は150μｍ、粒子形状は擬似
球形であった。Example 3 L was used as an initiator in 100 parts by weight of the starting monomer of Reference Example 2.
-0.55 parts by weight of ascorbic acid was mixed / dissolved to obtain a liquid C. Next, 1.9 parts by weight of hydrogen peroxide having a concentration of 31% by weight as an initiator was mixed / homogenized with 100 parts by weight of the raw material monomer of Reference Example 2 to obtain a liquid D. Liquid C and liquid D were supplied to the polymerization vessel shown in FIG. 1 and polymerized. The polymerization conditions were the same as in Example 1. The polymerization started about 3 seconds after the supply of the liquid C and the liquid D in the gas phase flow already supplied as droplets, and ended about 5 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. The polymer had a water absorption of 760 times its own weight after drying with respect to pure water, an average particle size of 150 μm, and a pseudo spherical shape.

実施例４ 重合器の気相流れ条件を、重合器入口の気相温度60
℃、重合部の気流平均流速1.3M/秒、原料であるＣ液と
Ｄ液の供給を、供給速度0.2リットル／分に変更した以
外は実施例３と同一条件で実施した。重合物は、乾燥後
の純水に対する吸水量が自重の720倍であるものであ
り、平均粒径は210μｍ、粒子形状は擬似球形であっ
た。Example 4 The gas phase flow conditions of the polymerization reactor were changed to a gas phase temperature of 60 at the polymerization reactor inlet.
Example 3 was carried out under the same conditions as in Example 3 except that the supply of the liquids C and D as raw materials was changed to 0.2 L / min. The polymer had a water absorption of 720 times its own weight after drying with respect to pure water, an average particle size of 210 μm, and a pseudo spherical shape.

実施例５ 重合器の気相流れ条件を、窒素雰囲気下から空気雰囲
気下に変更した以外は実施例１と同一条件で実施した。
重合物は、乾燥後の純水に対する吸水量が自重の740倍
であるものであり、平均粒径は150μｍ、粒子形状は擬
似球形であった。Example 5 Example 5 was carried out under the same conditions as in Example 1, except that the gas phase flow conditions of the polymerization vessel were changed from a nitrogen atmosphere to an air atmosphere.
The polymer had a water absorption of 740 times its own weight with respect to pure water after drying, and had an average particle size of 150 μm and a particle shape of pseudo sphere.

実施例６ 参考例３の原料モノマー100重量部に開始剤としてＬ
−アスコルビン酸0.75重量部を混合／溶解し、Ｅ液とし
た。次に、同じ参考例３の原料モノマー100重量部に開
始剤として濃度31重量％の過酸化水素水2.5重量部を混
合／均一化し、Ｆ液とした。Ｅ液とＦ液は、第１図の重
合器に供給され、重合された。重合器の気相流れ条件
は、実施例１と同一とした。また、原料であるＥ液とＦ
液の供給条件は、実施例１と同一とした。重合は、約１
秒後に、すでに液滴として供給された気相流中で開始
し、開始後約10秒で終了した。原料モノマーの供給、及
び得られた重合物の固気分離は、連続的に実施された。
重合物は、乾燥後の純水に対する吸水量が自重の680倍
であるものであり、平均粒径は140μｍ、粒子形状は擬
似球形であった。Example 6 L was used as an initiator in 100 parts by weight of the starting monomer of Reference Example 3.
-0.75 parts by weight of ascorbic acid was mixed / dissolved to obtain a solution E. Next, 2.5 parts by weight of a hydrogen peroxide solution having a concentration of 31% by weight as an initiator was mixed / homogenized with 100 parts by weight of the raw material monomer of Reference Example 3 to obtain a liquid F. The solution E and the solution F were supplied to the polymerization vessel shown in FIG. 1 and were polymerized. The gas phase flow conditions of the polymerization vessel were the same as in Example 1. Also, the raw material E liquid and F liquid
The liquid supply conditions were the same as in Example 1. The polymerization is about 1
Seconds later, it started in the gas phase flow already supplied as droplets and ended approximately 10 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed.
The polymer had a water absorption with respect to pure water after drying of 680 times its own weight, an average particle size of 140 μm, and a pseudo spherical shape.

実施例７ 重合器の気相流れ条件を、重合器入口の気相温度60
℃、重合部の気流平均流速1.3M/秒、に変更した以外は
実施例６と同一条件で実施した。重合物は、乾燥後の純
水に対する吸水量が自重の620倍であるものであり、平
均粒径は140μｍ、粒子形状は擬似球形であった。Example 7 The gas phase flow conditions of the polymerization reactor were changed to a gas phase temperature of 60 at the polymerization reactor inlet.
The procedure was performed under the same conditions as in Example 6 except that the temperature was changed to 1.3 ° C. and the average gas flow velocity in the polymerization section to 1.3 M / sec. The polymer had a water absorption with respect to pure water after drying of 620 times its own weight, an average particle size of 140 μm, and a particle shape of a pseudo spherical shape.

実施例８ 参考例２の原料モノマーを重合器入口温度70℃、モノ
マー供給ノズルとして（株）イケウチ製の充円錐ノズル
1/4MJ020S316Wを設置し供給圧力2kg/cm2、供給速度0.2
リットル／分で供給した以外は実施例１と同一の供給条
件にて、第２図の重合器（300cmφ×660cm）に供給し、
重合した。重合開始のため用いられたのは、ダイナミト
ロン加速機を装備した電子線装置で線量20メガラドにて
実施した。重合器の気相流れ条件は、重合器入口の気相
温度70℃以外は、実施例１と同一条件で実施した。重合
は、重合器に原料モノマー供給後、電子線が照射され直
ちに、すでに液滴として供給された気相流中で開始し、
開始後約５秒で重合器より流出させた。原料モノマーの
供給、及び得られた重合物の固気分離は連続的に実施さ
れた。重合物は、乾燥後の純水に対する吸水量が自重の
640倍であるものであって、平均粒径は160μｍ、粒子形
状は擬似球形であった。Example 8 A charged conical nozzle manufactured by Ikeuchi Co., Ltd. was prepared by using the raw material monomer of Reference Example 2 at a polymerization reactor inlet temperature of 70 ° C. and a monomer supply nozzle.
Install 1 / 4MJ020S316W, supply pressure 2kg / cm 2 , supply speed 0.2
Under the same supply conditions as in Example 1 except that the supply was performed at a rate of 1 liter / minute, the mixture was supplied to the polymerization vessel (300 cm φ × 660 cm) in FIG.
Polymerized. The electron beam apparatus equipped with a Dynamitron accelerator was used at a dose of 20 Mrad to initiate the polymerization. The gas phase flow conditions of the polymerization reactor were the same as in Example 1 except for the gas phase temperature at the polymerization reactor inlet of 70 ° C. Polymerization starts immediately after the raw material monomer is supplied to the polymerization vessel and is irradiated with an electron beam in a gas phase flow already supplied as droplets,
About 5 seconds after the start, the polymer was discharged from the polymerization vessel. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. The polymer absorbs its own weight with respect to pure water after drying.
The average particle diameter was 160 μm, and the particle shape was pseudo spherical.

実施例９ 参考例３の原料モノマーを実施例８と同一の供給条件
にて、第２図の重合器に供給し、重合した。重合開始の
ため用いられたのは、ダイナミトロン加速機を装備した
電子線装置で線量20メガラドにて実施した。重合器の気
相流れ条件は、重合器入口の気相温度70℃以外は、実施
例６と同一条件で実施した。重合は、重合器に原料モノ
マー供給後、電子線が照射され直ちに、すでに液滴とし
て供給された気相流中で開始し、開始後約５秒で終了し
た。原料モノマーの供給、及び得られた重合物の固気分
離は連続的に実施された。重合物は、乾燥後の純水に対
する吸水量が自重の620倍であるものであって、平均粒
径は130μｍ、粒子形状は擬似球形であった。Example 9 The raw material monomer of Reference Example 3 was supplied to the polymerization vessel shown in FIG. 2 under the same supply conditions as in Example 8 to perform polymerization. The electron beam apparatus equipped with a Dynamitron accelerator was used at a dose of 20 Mrad to initiate the polymerization. The conditions for the gas phase flow in the polymerization vessel were the same as in Example 6, except for the gas phase temperature at the polymerization vessel inlet at 70 ° C. The polymerization was started in the gas phase flow already supplied as droplets immediately after irradiation with the electron beam after the supply of the raw material monomers to the polymerization vessel, and was completed in about 5 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. The polymer had a water absorption of 620 times its own weight with respect to pure water after drying, had an average particle size of 130 μm, and had a pseudo spherical shape.

実施例10 参考例１の原料モノマー100重量部に増感剤として2,
2′−アゾビス（N,N′−ジメチレンイソブチルアミン）
２塩酸塩0.05重量部を混合／溶解し、この原料を重合器
入口温度50℃、相対湿度80％以外は実施例８と同一の供
給条件にて、第２図の重合器に供給し、重合した。重合
開始のために用いられたのは、高圧水銀ランプによる紫
外線照射で、該ランプは4KW×８灯（２灯対抗配置）、1
20W/cmにて実施した。重合器の気相流れ条件は、重合器
入口の気相温度50℃以外は、実施例１と同一条件で実施
した。重合は、重合器に原料モノマー供給後、紫外線が
照射され直ちに、すでに液滴として供給された気相流中
で開始し、開始後約20秒で重合器より流出させた。原料
モノマーの供給、及び得られた重合物の固気分離は連続
的に実施された。重合物は、乾燥後の純水に対する吸水
量が自重の800倍であるものであり、平均粒径は150μ
ｍ、粒子形状は擬似球形であった。Example 10 To 100 parts by weight of the raw material monomer of Reference Example 1, 2,2
2'-azobis (N, N'-dimethyleneisobutylamine)
0.05 parts by weight of dihydrochloride were mixed / dissolved, and this raw material was supplied to the polymerization reactor shown in FIG. 2 under the same supply conditions as in Example 8 except that the polymerization reactor inlet temperature was 50 ° C. and the relative humidity was 80%. did. UV irradiation by a high-pressure mercury lamp was used to initiate the polymerization. The lamp was 4KW x 8 lamps (2 lamps opposed to each other), 1
The test was performed at 20 W / cm. The conditions for the gas phase flow in the polymerization vessel were the same as in Example 1 except for the gas phase temperature at the polymerization vessel inlet of 50 ° C. The polymerization was started in the gas phase flow already supplied as droplets immediately after being irradiated with ultraviolet rays after supplying the raw material monomer to the polymerization vessel, and was discharged from the polymerization vessel about 20 seconds after the initiation. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. The polymer has a water absorption to pure water after drying of 800 times its own weight, and an average particle size of 150 μm.
m, the particle shape was pseudo spherical.

実施例11 増感剤として2,4−ジヒドロキシベンゾフェノンを参
考例２の原料モノマー100重量部に対して0.07重量部を
混合し、実施例８と同一の供給条件にて、第２図の重合
器に供給し、重合した。重合開始のために用いられたの
は、高圧水銀ランプによる紫外線照射で、該ランプは4K
W×４灯（２灯対抗配置）、80W/cm、及びダイナミトロ
ン加速機を装備した電子線装置（線量10メガラド）を直
列配置にて実施した。重合器の気相流れ条件は、重合器
入口の気相温度50℃以外は、実施例８と同一条件で実施
した。重合は、重合器に原料モノマー供給後、紫外線及
び電子線が照射され直ちに、すでに液滴として供給され
た気相流中で開始し、開始後約８秒で終了した。原料モ
ノマーの供給、及び得られた重合物の固気分離は連続的
に実施された。重合物は、乾燥後の純水に対する吸水量
が自重の620倍のものであり、平均粒径は150μｍ、粒子
形状は擬似球形であった。Example 11 2,4-Dihydroxybenzophenone was used as a sensitizer in an amount of 0.07 part by weight based on 100 parts by weight of the raw material monomer of Reference Example 2, and the polymerization reactor shown in FIG. And polymerized. UV irradiation by a high-pressure mercury lamp was used to initiate the polymerization.
An electron beam apparatus (dose of 10 Mrad) equipped with a W × 4 light (two light counter arrangement), 80 W / cm, and a dynamitron accelerator was implemented in a serial arrangement. The gas phase flow conditions of the polymerization vessel were the same as in Example 8, except for the gas phase temperature at the polymerization vessel inlet of 50 ° C. The polymerization started immediately after irradiation of ultraviolet rays and electron beams in the gas phase flow already supplied as droplets after the raw material monomers were supplied to the polymerization vessel, and was completed in about 8 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. The polymer had a water absorption with respect to pure water after drying of 620 times its own weight, an average particle size of 150 μm, and a pseudo spherical shape.

実施例12 参考例３の原料モノマー100重量部に増感剤として2,
2′−アゾビス（N,N′−ジメチレンイソブチルアミジ
ン）２塩酸塩0.04重量部を混合／溶解し、この原料を第
２図の重合器に供給し、重合した。重合開始のために用
いられたのは、高圧水銀ランプによる紫外線照射で、該
ランプは4KW/8灯（２灯対抗配置）120W/cmにて実施し
た。重合器の気相流れ条件は、重合器入口の気相温度50
℃以外は、実施例６と同一条件で実施した。また、原料
の供給条件は実施例８と同一とした。重合は、重合器に
原料モノマー供給後、紫外線が照射され直ちに、すでに
液滴として供給された気相流中で開始し、開始後約15秒
で終了した。原料モノマーの供給、及び得られた重合物
の固気分離は連続的に実施された。重合物は、乾燥後の
純水に対する吸水量が自重の690倍であるものであり、
平均粒径は150μｍ、粒子形状は擬似球形であった。Example 12 To 100 parts by weight of the raw material monomer of Reference Example 3, 2,2 was used as a sensitizer.
0.04 parts by weight of 2'-azobis (N, N'-dimethyleneisobutylamidine) dihydrochloride was mixed / dissolved, and this raw material was supplied to a polymerization vessel shown in FIG. 2 to carry out polymerization. UV irradiation by a high-pressure mercury lamp was used for the initiation of polymerization, and the lamp was operated at 4 KW / 8 lamps (two lamps opposed to each other) at 120 W / cm. The gas phase flow condition of the polymerization vessel is set at 50
Except for ° C, the experiment was performed under the same conditions as in Example 6. The supply conditions of the raw materials were the same as in Example 8. The polymerization was started in the gas phase flow already supplied as droplets immediately after the irradiation of the ultraviolet rays after the supply of the raw material monomers to the polymerization vessel, and was completed in about 15 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. The polymer has a water absorption to pure water after drying of 690 times its own weight,
The average particle size was 150 μm, and the particle shape was pseudo spherical.

比較例１ 実施例１のＡ液、及びＢ液のそれぞれ100重量部に純
水120重量部をそれぞれ混合しモノマー濃度19.3重量％
の重合用原料液（Ｇ液、Ｈ液）を作成した。このＧ液、
Ｈ液を用いた以外は実施例１と同一の条件で重合を実施
した。得られた重合物は、含水状態で形態保持性がない
ものであった。Comparative Example 1 120 parts by weight of pure water were mixed with 100 parts by weight of the liquids A and B of Example 1, respectively, and the monomer concentration was 19.3% by weight.
(G solution, H solution) were prepared. This liquid G,
Polymerization was carried out under the same conditions as in Example 1 except that H solution was used. The obtained polymer was hydrated and had no form retention.

比較例２ 参考例２の原料モノマー100重量部に純水358重量部を
加えてモノマー濃度18重量％の重合用原料（Ｉ液）を作
成した。このＩ液を用いた以外は実施例８と同一条件で
重合を実施した。得られた重合物は、含水状態で形態保
持性がないものであった。Comparative Example 2 358 parts by weight of pure water was added to 100 parts by weight of the raw material monomer of Reference Example 2 to prepare a polymerization raw material (liquid I) having a monomer concentration of 18% by weight. Polymerization was carried out under the same conditions as in Example 8 except that this solution I was used. The obtained polymer was hydrated and had no form retention.

実施例13 実施例１に記載のＡ液、Ｂ液を用いて第１図の重合器
に供給して、重合させた。重合器の気相流れ条件は、過
熱された水蒸気雰囲気下、重合器入口の気相温度150
℃、相対湿度90％、重合部の気流平均流速0.9M/秒であ
った。原料であるＡ液とＢ液の供給条件は、実施例１と
同一である。重合は、約１秒後に、すでに液滴として供
給された気相流中で開始され、開始後約５秒で終了し
た。原料モノマーの供給及び得られた重合物の固気分離
は、連続的に実施した。重合物は、乾燥後、純水に対す
る吸水量が自重の770倍のものであり、平均粒径130μ
ｍ、粒子形状は擬似球形を示した。Example 13 The solution A and the solution B described in Example 1 were supplied to the polymerization vessel shown in FIG. 1 for polymerization. The gas phase flow conditions of the polymerization reactor are as follows.
° C, relative humidity 90%, average flow velocity of the polymerization section was 0.9 M / sec. The supply conditions of the liquids A and B as the raw materials are the same as in the first embodiment. The polymerization was started after about 1 second in the gas phase stream already supplied as droplets and ended about 5 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. After drying, the polymer has a water absorption of 770 times its own weight with respect to pure water and an average particle size of 130 μm.
m and the particle shape showed a pseudo spherical shape.

実施例14 重合器の気相流れ条件を、重合部の気流平均流速1.3M
/秒、原料であるＡ液とＢ液の供給条件を、供給圧力2kg
/cm2、供給速度0.1リットル／分に変更した以外は実施
例13と同一条件で重合等を実施した。重合物は、乾燥
後、純水に対する吸水量が自重の740倍のものであり、
平均粒径190μｍ、粒子形状は擬似球形を示した。Example 14 The gas phase flow conditions of the polymerization vessel, the gas stream average flow velocity of the polymerization section 1.3M
Per second, supply conditions of liquid A and liquid B as raw material, supply pressure 2kg
/ cm 2, except for changing the feed rate of 0.1 l / min was carried out polymerization under the same conditions as in Example 13. After drying, the polymer has a water absorption to pure water of 740 times its own weight,
The average particle diameter was 190 μm, and the particle shape was a pseudo spherical shape.

実施例15 実施例３に記載のＣ液、Ｄ液を用いて実施例13と同一
条件で実施した。重合は、Ｃ液とＤ液の供給後、約１秒
後に、すでに液滴として供給された気相流中で開始し、
開始後約４秒で終了した。原料モノマーの供給、及び得
られた重合物の固気分離は、連続的に実施された。重合
物は、乾燥後、純水に対する吸水量が自重の690倍のも
のであり、平均粒径150μｍ、粒子形状は擬似球形を示
した。Example 15 The same procedure as in Example 13 was carried out using the solution C and the solution D described in Example 3. The polymerization starts about 1 second after the supply of the liquid C and the liquid D in the gas phase flow already supplied as droplets,
It ended about 4 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. After drying, the polymer had a water absorption of 690 times its own weight with respect to pure water, an average particle size of 150 μm, and a particle shape of a pseudo spherical shape.

実施例16 重合器の気相流れ条件を、重合器入口の気相温度150
℃、重合部の気流平均流速1.3M/秒、原料であるＣ液と
Ｄ液の供給条件を、供給圧力2kg/cm2、供給速度0.1リッ
トル／分に変更した以外は実施例15と同一条件で重合等
を実施した。重合物は、乾燥後、純水に対する吸水量が
自重の650倍のものであり、平均粒径210μｍ、粒子形状
は擬似球形を示した。Example 16 The gas phase flow conditions of the polymerization vessel, the gas phase temperature of the polymerization vessel inlet 150
The same conditions as in Example 15 except that the supply conditions of the liquid C and the liquid D as the raw materials were changed to 2 kg / cm 2 and the supply rate of 0.1 liter / min. Polymerization was carried out. After drying, the polymer had a water absorption with respect to pure water of 650 times its own weight, an average particle size of 210 μm, and a particle shape showing a pseudo spherical shape.

実施例17 重合器の気相流れ条件を、過熱された水蒸気雰囲気
下、重合器入口の気相温度150℃、相対湿度90％、重合
部の気流平均流速0.8M/秒、に変更した以外は実施例６
と同一条件で実施した。重合物は、乾燥後の純水に対す
る吸水量が自重の700倍であるものであり、平均粒径は1
30μｍ、粒子形状は擬似球形であった。Example 17 The gas phase flow conditions of the polymerization vessel were changed to a gas phase temperature of 150 ° C. at the polymerization vessel inlet, a relative humidity of 90%, and an average gas flow velocity of 0.8 M / sec in the polymerization section under a superheated steam atmosphere. Example 6
The test was performed under the same conditions as described above. The polymer has a water absorption to pure water after drying of 700 times its own weight and an average particle size of 1
30 μm, the particle shape was pseudo spherical.

実施例18 原料モノマーを実施例８と同一の供給条件にて、第２
図の重合器に供給し、重合させた。重合開始のために用
いられたのは、ダイナミトロン加速機を装備した電子線
装置で線量20メガラドにて実施した。重合器の気相流れ
条件を、重合器入口の気相温度160℃、相対湿度70％に
した以外は、実施例８と同一条件で重合等を実施した。
重合は、重合器に原料モノマー供給後、電子線が照射さ
れ直ちに、すでに液滴として供給された気相流中で開始
し、開始後約４秒で終了した。原料モノマーの供給及び
得られた重合物の固気分離は連続的に実施した。重合物
は、乾燥後、純水に対する吸水量が自重の580倍のもの
であり、平均粒径170μｍ、粒子形状は擬似球形を示し
た。Example 18 Under the same feeding conditions as in Example 8,
The mixture was supplied to the polymerization vessel shown in the figure and polymerized. The initiation of the polymerization was carried out with an electron beam device equipped with a Dynamitron accelerator at a dose of 20 Mrad. Polymerization and the like were carried out under the same conditions as in Example 8, except that the gas phase flow conditions of the polymerization vessel were set to 160 ° C. gas phase temperature and 70% relative humidity at the polymerization vessel inlet.
The polymerization was started in the gas phase flow already supplied as droplets immediately after being irradiated with the electron beam after the raw material monomer was supplied to the polymerization vessel, and was completed in about 4 seconds after the start. Supply of the raw material monomer and solid-gas separation of the obtained polymer were continuously carried out. After drying, the polymer had a water absorption with respect to pure water of 580 times its own weight, an average particle size of 170 μm, and a particle shape showing a pseudo spherical shape.

実施例19 実施例10の原料を、重合器入口の気相温度160℃、相
対湿度85％とした以外は、実施例10と同一の供給条件に
て、第２図の重合器に供給し、重合させた。重合開始の
ため用いられたのは、高圧水銀ランプによる紫外線照射
で、該ランプは4KW×８灯（２灯対抗配置）120W/cmであ
った。重合は、重合器に原料モノマー供給後、紫外線が
照射され直ちに、すでに液滴として供給された気相流中
で開始し、開始後約８秒で終了した。原料モノマーの供
給及び得られた重合物の固気分離は、連続的に実施し
た。重合物は、乾燥後、純水に対する吸水量が自重の76
0倍のものであり、平均流径150μｍ、粒子形状は擬似球
形を示した。Example 19 The raw material of Example 10 was supplied to the polymerization reactor of FIG. 2 under the same supply conditions as in Example 10 except that the gas phase temperature at the polymerization reactor inlet was 160 ° C. and the relative humidity was 85%. Polymerized. UV irradiation by a high-pressure mercury lamp was used to initiate the polymerization, and the lamp was 4 KW × 8 lamps (two lamps opposed to each other) 120 W / cm. The polymerization was started in the gas phase flow already supplied as droplets immediately after being irradiated with ultraviolet rays after supplying the raw material monomers to the polymerization vessel, and was completed in about 8 seconds after the start. The supply of the raw material monomer and the solid-gas separation of the obtained polymer were continuously performed. After drying, the polymer has a water absorption of
It had a mean flow diameter of 150 μm and a particle shape of pseudo spherical.

比較例３ 重合器の気相流れ条件を、過熱された乾燥空気130℃
雰囲気下とした以外は、実施例１と同一の条件で重合を
行なった。重合は、Ａ液とＢ液の供給後、約２秒後に、
すでに液滴として供給された気相流中で開始し、開始後
約３秒で停止した。重合物は、水溶性ポリマーであり、
未反応のアクリル酸及びアクリル酸ナトリウムが70重量
％、得られた重合物中から検出された。平均粒径は130
μｍ、粒子形状は擬似球形であった。Comparative Example 3 The gas phase flow conditions of the polymerization vessel were changed to 130 ° C. of superheated dry air.
Polymerization was carried out under the same conditions as in Example 1 except that the atmosphere was changed. The polymerization is performed about 2 seconds after the supply of the solution A and the solution B,
It started in the gas phase flow already supplied as droplets and stopped about 3 seconds after the start. The polymer is a water-soluble polymer,
Unreacted acrylic acid and sodium acrylate were detected in 70% by weight of the obtained polymer. Average particle size is 130
μm, the particle shape was pseudo spherical.

実施例20 参考例１の原料モノマー100重量部に開始剤としてＬ
−アスコルビン酸0.55重量部を混合／溶解して、Ｊ液と
した。次に、同じ参考例１の原料モノマー100重量部に
開始剤として濃度31重量％の過酸化水素水1.9重量部を
混合／均一化して、Ｋ液とした。Ｊ液とＫ液は、第１図
の重合器に供給して、重合させた。重合器の気相流れ条
件は、過熱された水蒸気雰囲気下、重合器入口の気相温
度180℃、相対湿度80％、重合部の気流平均流速0.9M/秒
であった。原料であるＪ液とＫ液の混合液の供給条件
は、実施例１と同じである。重合器内壁面温度は、ジャ
ケットにスチームを通すことによって230℃に設定した
（重合系の気相より50℃高温）。重合は、Ｊ液とＫ液の
供給後、約１秒後に、すでに液滴として供給された気相
流中で開始し、開始後約５秒で重合器より流出させた。
原料モノマーの供給及び得られた重合物の固気分離は、
連続的に実施した。重合物は、乾燥後、純水に対する吸
水量が自重の690倍のものであり、平均粒径150μｍ、粒
子形状は擬似球形を示した。24時間連続運転後の重合器
内壁面付着量は、表１に示す通りであった。Example 20 L was used as an initiator in 100 parts by weight of the starting monomer of Reference Example 1.
-Ascorbic acid (0.55 parts by weight) was mixed / dissolved to obtain solution J. Next, 1.9 parts by weight of a hydrogen peroxide solution having a concentration of 31% by weight as an initiator was mixed / homogenized with 100 parts by weight of the raw material monomer of Reference Example 1 to obtain a liquid K. The solution J and the solution K were supplied to the polymerization vessel shown in FIG. 1 to be polymerized. The gas phase flow conditions of the polymerization vessel were as follows: under a superheated steam atmosphere, the gas phase temperature at the polymerization vessel inlet was 180 ° C., the relative humidity was 80%, and the average gas flow velocity in the polymerization section was 0.9 M / sec. The supply conditions of the mixed liquid of the J liquid and the K liquid as the raw materials are the same as in the first embodiment. The inner wall temperature of the polymerization vessel was set to 230 ° C. by passing steam through the jacket (50 ° C. higher than the polymerization gas phase). The polymerization was started about 1 second after the supply of the liquids J and K in the gas phase flow already supplied as droplets, and was discharged from the polymerization vessel about 5 seconds after the start.
The supply of the raw material monomer and the solid-gas separation of the obtained polymer are:
Performed continuously. After drying, the polymer had a water absorption of 690 times its own weight with respect to pure water, an average particle size of 150 μm, and a particle shape of pseudo spherical. The amount of adhesion to the inner wall of the polymerization vessel after the continuous operation for 24 hours was as shown in Table 1.

実施例21−25 重合器内壁面温度を変更した以外は、実施例20と同一
条件にて重合等を実施した。24時間連続運転後の重合器
内付着量は、表１に示す通りであった。Examples 21 to 25 Polymerization and the like were carried out under the same conditions as in Example 20, except that the inner wall surface temperature of the polymerization vessel was changed. The adhesion amount in the polymerization vessel after continuous operation for 24 hours was as shown in Table 1.

実施例26 参考例２の原料モノマーを、実施例８と同一の供給条
件にて第２図の重合器に供給して、重合させた。重合開
始のために用いたのは、ダイナミトロン加速機を装備し
た電子線装置による線量20メガラドの電子線照射であっ
た。重合器の気相流れ条件は、重合器入口の気相温度11
0℃、相対湿度95％、重合器内壁面温度を210℃とした以
外は、実施例13と同一であった。重合は、重合器に原料
モノマー供給後、電子線が照射されると直ちに、すでに
液滴として供給された気相流中で開始し、開始後約４秒
で重合器より流出させた。原料モノマーの供給及び得ら
れた重合物の固気分離は連続的に実施した。重合物は、
乾燥後、純水に対する吸水量が自重の600倍のものであ
り、平均粒径160μｍ、粒子形状は擬似球形を示した。2
4時間連続運転後、重合器内壁面付着量は、表２に示す
通りであった。Example 26 The raw material monomer of Reference Example 2 was supplied to the polymerization vessel shown in FIG. 2 under the same supply conditions as in Example 8 for polymerization. The electron beam irradiation with a dose of 20 megarads was performed using an electron beam apparatus equipped with a dynamitron accelerator to initiate the polymerization. The gas-phase flow conditions of the polymerization reactor are determined by the gas-phase temperature at the polymerization reactor inlet 11
Example 13 was the same as Example 13 except that the temperature was 0 ° C, the relative humidity was 95%, and the inner wall surface temperature of the polymerization vessel was 210 ° C. The polymerization was started in the gas phase flow already supplied as droplets immediately after the irradiation of the electron beam after the supply of the raw material monomer to the polymerization vessel, and was discharged from the polymerization vessel about 4 seconds after the initiation. Supply of the raw material monomer and solid-gas separation of the obtained polymer were continuously carried out. The polymer is
After drying, the water absorption with respect to pure water was 600 times its own weight, the average particle size was 160 μm, and the particle shape was pseudo-spherical. Two
After the continuous operation for 4 hours, the adhesion amount on the inner wall of the polymerization vessel was as shown in Table 2.

実施例27−31 重合器内壁面温度を変更した以外は、実施例26と同一
条件にて重合等を実施した。24時間連続運転後の重合器
内壁面付着量は、表２に示す通りであった。Examples 27 to 31 Polymerization and the like were carried out under the same conditions as in Example 26 except that the inner wall temperature of the polymerization vessel was changed. The amount of adhesion to the inner wall of the polymerization vessel after continuous operation for 24 hours was as shown in Table 2.

実施例32 参考例２の原料モノマー100重量部に増感剤として2,4
−ジヒドロキシベンゾフェノン0.07重量部を混合し／溶
解し、この原料を、重合器入口温度50℃以外は実施例８
と同一の供給条件にて第２図の重合器に供給して、重合
させた。重合開始のために用いたのは、高圧水銀ランプ
による紫外線照射で、該ランプは4KW×８灯（２灯対向
配置）、120W/cmであった。重合器の気相流れ条件は、
重合器入口の気相温度110℃、相対湿度95％以外は、実
施例８と同一であった。重合は、重合器に原料モノマー
供給後、紫外線が照射されると直ちに、すでに液滴とし
て供給された気相流中で開始し、開始後約８秒で終了し
た。原料モノマーの供給及び得られた重合物の固気分離
は連続的に実施した。重合物は、乾燥後、純水に対する
吸水量が自重の760倍のものであり、平均粒径150μｍ、
粒子形状は擬似球形を示した。24時間連続運転後、重合
器内壁面付着量は、表３に示す通りであった。Example 32 2,4 as a sensitizer was added to 100 parts by weight of the raw material monomer of Reference Example 2.
0.08 parts by weight of dihydroxybenzophenone were mixed / dissolved.
Under the same supply conditions as described above, the mixture was supplied to the polymerization vessel shown in FIG. UV irradiation by a high-pressure mercury lamp was used to initiate the polymerization, and the lamp was 4 KW × 8 lamps (two lamps facing each other) and 120 W / cm. The gas phase flow conditions of the polymerization vessel are:
Example 8 was the same as Example 8 except that the gas phase temperature at the polymerization reactor inlet was 110 ° C and the relative humidity was 95%. The polymerization was started in the gas phase flow already supplied as droplets immediately after the irradiation of the ultraviolet rays after the supply of the raw material monomers to the polymerization reactor, and ended in about 8 seconds after the start. Supply of the raw material monomer and solid-gas separation of the obtained polymer were continuously carried out. After drying, the polymer has a water absorption of 760 times its own weight with respect to pure water, an average particle size of 150 μm,
The particle shape was a pseudo spherical shape. After the continuous operation for 24 hours, the adhesion amount on the inner wall of the polymerization vessel was as shown in Table 3.

実施例33−37 重合器内壁面温度を変更した以外は、実施例32と同一
条件にて重合等を実施した。24時間連続運転後の重合器
内付着量は、表３に示す通りであった。Examples 33 to 37 Polymerization and the like were carried out under the same conditions as in Example 32 except that the inner wall temperature of the polymerization vessel was changed. The amount of adhesion in the polymerization vessel after continuous operation for 24 hours was as shown in Table 3.

【図面の簡単な説明】[Brief description of the drawings]

第１〜２図は、本発明で使用する重合装置の具体例の二
例をそれぞれ示す説明図である。 第３図は、第１図の装置に乾燥装置を付帯させた一具体
例を示す説明図である。 第４図は、第１図の装置の改変例を示す説明図である。 １……重合器（スチームジャケット付）、２……原料モ
ノマー供給ノズル、３……気流分散板、４……原料モノ
マー供給ライン、５……気流供給ライン、6,15……気流
加熱機、７……気流供給ブロアー、８……気流調整用ダ
ンパー、９……気流補充ライン、10……気流廃棄ライ
ン、11……固機分離器、12……固体（重合物）排出ライ
ン、13……UV照射機、及び／あるいは高エネルギー線放
射機、14……気流循環ライン、16……乾燥処理部、17…
…エアーノッカー、18……スチーム供給ライン。FIGS. 1 and 2 are explanatory diagrams showing two specific examples of the polymerization apparatus used in the present invention. FIG. 3 is an explanatory diagram showing a specific example in which a drying device is added to the device of FIG. FIG. 4 is an explanatory view showing a modified example of the apparatus shown in FIG. DESCRIPTION OF SYMBOLS 1 ... Polymerizer (with a steam jacket), 2 ... Material monomer supply nozzle, 3 ... Gas dispersion plate, 4 ... Material monomer supply line, 5 ... Gas supply line, 6,15 ... Gas heater 7 ... airflow supply blower, 8 ... airflow adjustment damper, 9 ... airflow replenishment line, 10 ... airflow disposal line, 11 ... solid-state separator, 12 ... solid (polymer) discharge line, 13 ... ... UV irradiator and / or high-energy ray radiator, 14 ... airflow circulation line, 16 ... drying processing unit, 17 ...
... Air knocker, 18 ... Steam supply line.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 吉永 憲司 三重県四日市市東邦町１番地 三菱油化 株式会社化成品研究所内 (56)参考文献 特許2642436（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.6，ＤＢ名) C08F 2/34──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Kenji Yoshinaga 1 Tohocho, Yokkaichi-shi, Mie Mitsubishi Chemical Co., Ltd. Chemical Products Research Laboratories (56) References Patent 2642436 (JP, B2) (58) Fields investigated ( Int.Cl. 6 , DB name) C08F 2/34

Claims (10)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】水溶性エチレン性不飽和モノマーを主成分
とするモノマー濃度が少なくとも20重量％の溶液を、水
蒸気又は水蒸気と他の少なくとも一種の重合に実質的に
不活性性を示す気体との混合物からなる気相を収容する
重合器に液滴として供給し、該気相中、気相の相対湿度
30％以上の条件下で重合させることを特徴とする、吸水
性樹脂の製造法。1. A solution comprising a water-soluble ethylenically unsaturated monomer as a main component and having a monomer concentration of at least 20% by weight, is mixed with steam or steam and at least one other gas which is substantially inert to polymerization. The mixture is supplied as droplets to a polymerization vessel containing a vapor phase, and the relative humidity of the vapor phase in the vapor phase
A method for producing a water-absorbent resin, comprising polymerizing under a condition of 30% or more. 【請求項２】水溶性エチレン性不飽和モノマーが（メ
タ）アクリル酸及び／又はその塩であることを特徴とす
る、請求項１に記載の吸水性樹脂の製造法。2. The method for producing a water-absorbent resin according to claim 1, wherein the water-soluble ethylenically unsaturated monomer is (meth) acrylic acid and / or a salt thereof. 【請求項３】水溶性エチレン性不飽和モノマーがアクリ
ル酸の部分中和塩であることを特徴とする、請求項１に
記載の吸水性樹脂の製造法。3. The method for producing a water-absorbent resin according to claim 1, wherein the water-soluble ethylenically unsaturated monomer is a partially neutralized salt of acrylic acid. 【請求項４】前記溶液が、そのカルボキシル基の20％以
上〜95％未満がナトリウム塩に中和されてなるアクリル
酸の部分中和塩を45〜80重量％含む水溶液であることを
特徴とする、請求項１に記載の吸水性樹脂の製造法。4. An aqueous solution containing 45 to 80% by weight of a partially neutralized salt of acrylic acid in which at least 20% to less than 95% of the carboxyl group is neutralized to a sodium salt. The method for producing a water-absorbent resin according to claim 1. 【請求項５】前記溶液が、そのカルボキシル基の40％以
上がカリウム塩に中和されてなるアクリル酸の部分中和
塩を45〜80重量％含む水溶液であることを特徴とする、
請求項１に記載の吸水性樹脂の製造法。5. The method according to claim 1, wherein the solution is an aqueous solution containing 45 to 80% by weight of a partially neutralized salt of acrylic acid in which at least 40% of the carboxyl groups are neutralized with a potassium salt.
A method for producing the water absorbent resin according to claim 1. 【請求項６】前記気相が空気及び／又は窒素と水蒸気と
の混合物からなることを特徴とする、請求項１〜５のい
ずれか一項に記載の吸水性樹脂の製造法。6. The method for producing a water-absorbing resin according to claim 1, wherein the gas phase comprises a mixture of air and / or nitrogen and water vapor. 【請求項７】前記気相が水蒸気又は水蒸気及び空気から
なることを特徴とする、請求項１〜５のいずれか一項に
記載の吸水性樹脂の製造法。7. The method for producing a water-absorbent resin according to claim 1, wherein the gas phase comprises steam or steam and air. 【請求項８】重合が水溶性ラジカル重合開始剤を用いて
行われることを特徴とする、請求項１〜７のいずれか一
項に記載の吸水性樹脂の製造法。8. The method for producing a water-absorbent resin according to claim 1, wherein the polymerization is carried out using a water-soluble radical polymerization initiator. 【請求項９】水溶性ラジカル重合開始剤がレドックス開
始剤であることを特徴とする、請求項８に記載の吸水性
樹脂の製造法。9. The method for producing a water-absorbent resin according to claim 8, wherein the water-soluble radical polymerization initiator is a redox initiator. 【請求項１０】重合器内壁温度が重合温度より少なくと
も10℃高く設定されていることを特徴とする、請求項１
〜９のいずれか一項に記載の吸水性樹脂の製造法。10. The method according to claim 1, wherein the temperature of the inner wall of the polymerization vessel is set at least 10 ° C. higher than the polymerization temperature.
10. The method for producing a water-absorbent resin according to any one of claims 9 to 9.
JP15660189A 1988-06-22 1989-06-19 Manufacturing method of water absorbent resin Expired - Fee Related JP2781208B2 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP15660189A JP2781208B2 (en) 1988-06-22 1989-06-19 Manufacturing method of water absorbent resin
EP19890306270 EP0348180A3 (en) 1988-06-22 1989-06-21 Process for the preparation of water absorptive resin
KR1019890008652A KR970009231B1 (en) 1988-06-22 1989-06-22 Process for the preparation of water-absorptive resin

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
JP63-154188 1988-06-22
JP15418888 1988-06-22
JP20299588 1988-08-15
JP63-202995 1988-08-15
JP21590588 1988-08-30
JP63-215905 1988-08-30
JP15660189A JP2781208B2 (en) 1988-06-22 1989-06-19 Manufacturing method of water absorbent resin

Publications (2)

Publication Number Publication Date
JPH02138306A JPH02138306A (en) 1990-05-28
JP2781208B2 true JP2781208B2 (en) 1998-07-30

Family

ID=27473276

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15660189A Expired - Fee Related JP2781208B2 (en) 1988-06-22 1989-06-19 Manufacturing method of water absorbent resin

Country Status (1)

Country Link
JP (1) JP2781208B2 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3950743B2 (en) * 2002-06-03 2007-08-01 キヤノン株式会社 Method for producing toner particles
DE102005002412A1 (en) * 2005-01-18 2006-07-27 Basf Ag Process for the preparation of polymers by spray polymerization
CN101489597A (en) * 2006-07-19 2009-07-22 巴斯夫欧洲公司 Method for producing water-absorbing polymer particles by polymerizing droplets of a monomer solution
DE502007003770D1 (en) * 2006-07-19 2010-06-24 Basf Se METHOD FOR PRODUCING WATER ABSORBING POLYMER PARTICLES WITH HIGH PERMEABILITY BY POLYMERIZATION OF DROPS OF A MONOMER SOLUTION
RU2463310C2 (en) * 2006-07-19 2012-10-10 Басф Се Method of producing water-absorbing polymer particles with high permeability by polymerising droplets of monomer solution
BRPI0720482B8 (en) * 2006-12-22 2021-07-27 Basf Se process to produce water-absorbent polymeric particles, water-absorbent polymeric particles, use of polymeric particles, and, sanitary article
CN101605821A (en) * 2007-02-06 2009-12-16 巴斯夫欧洲公司 Produce the method for polymer beads by polymerisation of liquid droplets in gas phase
US10252238B2 (en) * 2015-03-02 2019-04-09 Basf Se Apparatus for producing pulverulent poly(meth)acrylate

Also Published As

Publication number Publication date
JPH02138306A (en) 1990-05-28

Similar Documents

Publication Publication Date Title
KR970009231B1 (en) Process for the preparation of water-absorptive resin
US5059664A (en) Process for the preparation of water absorptive resin
JP6494520B2 (en) Super absorbent manufacturing method based on recycled raw materials
TWI418567B (en) Method for producing water absorbent resin
JP5730194B2 (en) Method for producing water-absorbing polymer particles
ZA200602473B (en) Spray polymerisation method
JPH06345819A (en) Production of highly water absorbing resin
JP2011515520A (en) Method for producing water-absorbing polymer particles having a low centrifuge retention capacity
JPH01207327A (en) Surface treating method of water absorbing resin
JP2781208B2 (en) Manufacturing method of water absorbent resin
JPH07224204A (en) Production of water-absorbing resin
JP5611191B2 (en) Method for producing water-absorbing polymer particles
JP2642436B2 (en) Manufacturing method of water absorbent resin
JPH1045812A (en) Production of fiber-containing water absorbing resin
JP4107775B2 (en) Manufacturing method of super absorbent resin
JPH01249808A (en) Production of salt-resistant water-absorbable resin particle
JPH03137129A (en) Pelletizing method of granular material
JPH02215801A (en) Preparation of liquid-swelling polymer
JP2009506132A (en) Method for producing modified water-absorbing resin
JP7374175B2 (en) Method of manufacturing superabsorbents
JP2642436C (en)
JP5794991B2 (en) Use of heated vapor condensate to produce water-absorbing polymer particles
EP3880354A1 (en) Process for producing superabsorbents
CN114874378B (en) Preparation method of high-absorptivity resin
JP7497826B2 (en) Method for producing a superabsorbent

Legal Events

Date Code Title Description
LAPS Cancellation because of no payment of annual fees