JPH08157531A - Production of highly water-absorbing resin - Google Patents
Production of highly water-absorbing resinInfo
- Publication number
- JPH08157531A JPH08157531A JP33106494A JP33106494A JPH08157531A JP H08157531 A JPH08157531 A JP H08157531A JP 33106494 A JP33106494 A JP 33106494A JP 33106494 A JP33106494 A JP 33106494A JP H08157531 A JPH08157531 A JP H08157531A
- Authority
- JP
- Japan
- Prior art keywords
- water
- weight
- resin
- organic solvent
- superabsorbent resin
- 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.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F8/00—Chemical modification by after-treatment
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、高吸水性樹脂の製造法
に関し、更に詳しくは荷重下での吸水力に優れ、「ママ
コ」の生成しない高吸水性樹脂の製造法に関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a highly water-absorbent resin, and more particularly to a method for producing a highly water-absorbent resin which is excellent in water absorption under load and does not produce "Mamako".
【０００２】[0002]
【従来の技術】高吸水性樹脂は、生理用品において、体
液を吸収し漏洩を防止する体液吸収剤として有用であ
り、そのほか、土壌の保水剤、種子コーティング剤、止
水剤、増粘剤、結露防止剤、乾燥剤、調湿剤などの用途
に使用されている。しかし、これらの高吸水性樹脂は、
吸水時に粒子間が膠着し、均一な吸水が阻害されるとい
う、いわゆる「ママコ」が生じて吸水性樹脂全体に水が
拡散せずに吸水速度が低下するものや衛生材料用途で重
視される荷重下での吸水力が低いという欠点を有してい
るものがある。BACKGROUND OF THE INVENTION Super absorbent polymers are useful as a body fluid absorbent for absorbing and preventing leakage of body fluids in sanitary products. In addition, a water retention agent for soil, a seed coating agent, a water blocking agent, a thickener, It is used for anti-condensation agents, desiccants, humidity control agents, etc. However, these super absorbent resins are
When water is absorbed, particles stick to each other and uniform water absorption is impeded, so-called "mamako" occurs, the water absorption rate decreases without water spreading throughout the water absorbent resin, and load that is important for sanitary material applications. Some of them have a drawback that they have a low water absorption capacity below.
【０００３】これらの欠点の改良技術として、高吸水性
樹脂に多価アルコールやそのオキシアルキレンエーテル
を添加する方法（特開昭５８−１８３７５４号公報）、
高吸水性樹脂に、無機質粉末の存在下で架橋剤及び水を
吸収せしめて架橋させる方法（特開昭６０−１６３９５
６号公報）、高吸水性樹脂にショ糖脂肪酸エステルを添
加し、水の存在下に架橋剤を用いて、架橋させる方法
（特開平３−２８２０３号公報）、高吸水性樹脂に水及
び無機質粉末の存在下、親水性不活性溶剤中で架橋剤を
用いて架橋させる方法（特開昭６０−１４７４７５号公
報）、予め界面活性剤の存在下で疎水性有機溶剤に分散
させた架橋剤を疎水性有機溶剤に高吸水性樹脂を分散さ
せた懸濁液に添加する方法（特開平１−２０７３２７号
公報）、高吸水性樹脂に、水及び界面活性剤の存在下、
不活性溶媒中で粉末状無機質を加えた後、水及び不活性
溶媒を留去する方法（特公平６−４３５００号公報）が
知られている。As a technique for improving these drawbacks, a method of adding a polyhydric alcohol or its oxyalkylene ether to a highly water-absorbent resin (JP-A-58-183754),
A method in which a superabsorbent resin is crosslinked by absorbing a crosslinking agent and water in the presence of an inorganic powder (JP-A-60-16395).
No. 6), sucrose fatty acid ester is added to the superabsorbent resin, and a crosslinking agent is used in the presence of water to crosslink (JP-A-3-28203). Water and inorganic substances are added to the superabsorbent resin. A method of crosslinking using a crosslinking agent in a hydrophilic inert solvent in the presence of powder (JP-A-60-147475), a crosslinking agent previously dispersed in a hydrophobic organic solvent in the presence of a surfactant. A method of adding to a suspension in which a superabsorbent resin is dispersed in a hydrophobic organic solvent (JP-A-1-207327), the superabsorbent resin in the presence of water and a surfactant,
A method (Japanese Patent Publication No. 6-43500) in which water and an inert solvent are distilled off after adding a powdered inorganic substance in an inert solvent is known.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、特開昭
５８−１８３７５４号公報開示技術では「ママコ」の生
成防止にはつながるものの、荷重下での吸水力の低下は
避けることができず、又特開昭６０−６３９５６号公
報、特開平３−２８２０３号公報及び特開昭６０−１４
７４７５号公報開示技術においては、多量の水の存在下
で架橋を行っているため、高吸水性樹脂が該水の一部を
吸水して、架橋剤の添加効果が十分得られず、その結果
「ママコ」の生成や荷重下での吸水力の低下という欠点
を有し、更に特開平１−２０７３２７号公報、特公平６
−４３５００号公報開示技術では、荷重下での吸水性の
十分な向上効果は得難いという欠点を有しており、水性
液体に接した時の「ママコ」の生成が抑制され、かつ荷
重下での吸水力に優れた高吸水性樹脂の製造法が望まれ
ているのである。However, although the technique disclosed in Japanese Patent Laid-Open No. 183754/1983 leads to the prevention of the formation of "Mamako", the decrease of the water absorption under load cannot be avoided, and JP-A-60-63956, JP-A-3-28203 and JP-A-60-14
In the technology disclosed in Japanese Patent No. 7475, since the crosslinking is carried out in the presence of a large amount of water, the superabsorbent resin absorbs part of the water, and the effect of adding the crosslinking agent cannot be sufficiently obtained. It has the drawback that "Mamako" is generated and the water absorption capacity is lowered under load, and further, it is disclosed in JP-A-1-207327 and JP-B-6.
The technology disclosed in JP-A-43500 has a drawback in that it is difficult to obtain a sufficient effect of improving water absorption under load, which suppresses the formation of "Mamako" when in contact with an aqueous liquid, and Therefore, a method for producing a highly water-absorbent resin excellent in water absorption is desired.
【０００５】[0005]
【課題を解決するための手段】本発明者らは、上記目的
を達成すべく鋭意研究を重ねた結果、含水率が３〜５０
重量％でかつカルボキシレート基を有する高吸水性樹脂
と、ショ糖脂肪酸エステルおよび／またはソルビタン脂
肪酸エステル、カルボキシレート基と反応しうる官能基
を２個以上有する架橋剤、及び水不溶性無機質粉末を有
機溶剤の存在下で混合した後、有機溶剤を留去して、次
いで加熱して架橋処理を行うことにより「ママコ」を生
成せず、かつ荷重下においても良好な吸水性を有する事
を見いだし、本発明を完成するに至った。以下に本発明
を詳細に記述する。Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that the water content is 3 to 50.
A highly water-absorbent resin having a weight percent and a carboxylate group, a sucrose fatty acid ester and / or a sorbitan fatty acid ester, a crosslinking agent having two or more functional groups capable of reacting with a carboxylate group, and a water-insoluble inorganic powder are organic. After mixing in the presence of a solvent, the organic solvent was distilled off, and then "Mamako" was not formed by heating and performing a crosslinking treatment, and it was found that it has good water absorption even under load, The present invention has been completed. The present invention is described in detail below.
【０００６】本発明の対象となる高吸水性樹脂として
は、分子内においてカルボキシレート基を有するもので
あれば特定されないが、具体的にはカルボキシレート基
を有すると共に、水中において多量の水を吸収して膨潤
しヒドロゲルを形成する樹脂である。ここでカルボキシ
レート基とはカルボキシル基あるいは／またはカルボン
酸塩基のことを言う。このような樹脂としては種々のも
のが知られており、例えば、デンプン−アクリロニトリ
ルグラフト共重合体の加水分解物、デンプン−アクリル
酸グラフト重合体の中和物、アクリル酸エステル−酢酸
ビニル共重合体のケン化物、アクリロニトリル共重合体
もしくはアクリルアミド共重合体の加水分解物、架橋ポ
リビニルアルコール変性物、自己架橋型ポリアクリル酸
中和物、ポリアクリル酸塩架橋体、架橋イソブチレン−
無水マレイン酸共重合体の中和物等を挙げることがで
き、これらに限定されるものではないが、中でもポリア
クリル酸塩架橋体、架橋ポリビニルアルコール変性物か
らなる高吸水性樹脂が重要である。The superabsorbent resin to which the present invention is applied is not specified as long as it has a carboxylate group in its molecule. Specifically, it has a carboxylate group and absorbs a large amount of water in water. It is a resin that swells and forms a hydrogel. Here, the carboxylate group means a carboxyl group and / or a carboxylate group. Various resins are known as such a resin, for example, a hydrolyzate of a starch-acrylonitrile graft copolymer, a neutralized product of a starch-acrylic acid graft polymer, an acrylic acid ester-vinyl acetate copolymer. Saponified product, hydrolyzate of acrylonitrile copolymer or acrylamide copolymer, crosslinked polyvinyl alcohol modified product, self-crosslinking polyacrylic acid neutralized product, polyacrylic acid salt crosslinked product, crosslinked isobutylene-
Examples thereof include, but are not limited to, neutralized products of maleic anhydride copolymers, but among them, polyacrylic acid salt crosslinked products and superabsorbent resins composed of crosslinked polyvinyl alcohol modified products are important. .
【０００７】該ポリアクリル酸塩架橋体からなる高吸水
性樹脂は通常、（メタ）アクリル酸及び（メタ）アクリ
ル酸水溶性塩の混合物からなるモノマーを重合すること
により得られる。水溶性塩としては、ナトリウム塩、カ
リウム塩、アンモニウム塩等が挙げられる。（メタ）ア
クリル酸及び（メタ）アクリル酸水溶性塩との混合割合
はモル比で１０／９０〜５０／５０の範囲から選択する
ことが望ましい。この範囲から外れると、得られる高吸
水性樹脂の吸収特性が低下するようになる。（メタ）ア
クリル酸及び（メタ）アクリル酸水溶性塩の混合物は、
通常（メタ）アクリル酸を水酸化ナトリウム、水酸化カ
リウム、アンモニアなどのアルカリで部分的に中和する
ことより得られる。これらのモノマーと共に、他のビニ
ルモノマー、例えば（メタ）アクリル酸エステル、不飽
和スルホン酸またはその塩、（メタ）アクリルアミド、
（メタ）アクリロニトリル、ビニルエステル、ビニルエ
ーテルなどを少量併用することも出来る。The highly water-absorbent resin composed of the crosslinked polyacrylic acid salt is usually obtained by polymerizing a monomer composed of a mixture of (meth) acrylic acid and a water-soluble salt of (meth) acrylic acid. Examples of the water-soluble salt include sodium salt, potassium salt, ammonium salt and the like. The mixing ratio of (meth) acrylic acid and the water-soluble salt of (meth) acrylic acid is preferably selected from the range of 10/90 to 50/50 in terms of molar ratio. If it deviates from this range, the absorption characteristics of the resulting superabsorbent polymer will deteriorate. A mixture of (meth) acrylic acid and a water-soluble salt of (meth) acrylic acid is
It is usually obtained by partially neutralizing (meth) acrylic acid with an alkali such as sodium hydroxide, potassium hydroxide or ammonia. In addition to these monomers, other vinyl monomers such as (meth) acrylic acid ester, unsaturated sulfonic acid or its salt, (meth) acrylamide,
A small amount of (meth) acrylonitrile, vinyl ester, vinyl ether, etc. can be used together.
【０００８】重合を実施するに当たっては、公知の任意
の方法が採用でき、水溶液重合（静置重合）、乳化重合
（逆相乳化重合）、懸濁重合（逆相懸濁重合）等がいず
れも可能であるが、好ましくは、逆相懸濁重合、あるい
は静置重合である。以下かかる重合方法について、更に
具体的に説明する。逆相懸濁重合を行うに際しては、水
に溶解しない有機溶剤中に（メタ）アクリル酸、（メ
タ）アクリル酸水溶性塩、望ましくは多官能性ビニルモ
ノマー等の架橋剤を含む水溶液を分散させてラジカル重
合開始剤の存在下で重合を行う。その際、公知の分散安
定剤や界面活性剤を共存させて重合の安定性をはかるこ
とも可能である。有機溶剤としては、シクロヘキサン、
シクロペンタン等の脂環式炭化水素、ｎ−ペンタン、ｎ
−ヘキサン、ｎ−ヘプタン、リグロイン等の脂肪族炭化
水素、ベンゼン、トルエン、キシレン等の芳香族炭化水
素が例示される。溶媒の融点、沸点、価格、工業的入手
の容易さから判断するとｎ−ヘキサンやシクロヘキサン
が最も実用的である。重合温度は５０〜９０℃、重合時
間は０．５〜５時間が適当である。重合終了後は常法に
従って、生成粒子を濾別し、洗浄、乾燥することにより
高吸水性樹脂が得られる。In carrying out the polymerization, any known method can be adopted, and any of aqueous solution polymerization (static polymerization), emulsion polymerization (reverse phase emulsion polymerization), suspension polymerization (reverse phase suspension polymerization) and the like can be used. Although possible, reverse phase suspension polymerization or static polymerization is preferable. The polymerization method will be described more specifically below. When carrying out reverse phase suspension polymerization, an aqueous solution containing (meth) acrylic acid, a water-soluble salt of (meth) acrylic acid, preferably a crosslinking agent such as a polyfunctional vinyl monomer is dispersed in an organic solvent that is insoluble in water. Polymerization is performed in the presence of a radical polymerization initiator. At that time, it is possible to improve the stability of the polymerization by coexisting a known dispersion stabilizer or surfactant. As the organic solvent, cyclohexane,
Alicyclic hydrocarbons such as cyclopentane, n-pentane, n
Examples thereof include aliphatic hydrocarbons such as -hexane, n-heptane and ligroin, and aromatic hydrocarbons such as benzene, toluene and xylene. Judging from the melting point, boiling point, price, and industrial availability of the solvent, n-hexane and cyclohexane are the most practical. It is suitable that the polymerization temperature is 50 to 90 ° C. and the polymerization time is 0.5 to 5 hours. After completion of the polymerization, the superabsorbent resin is obtained by filtering the produced particles, washing and drying according to a conventional method.
【０００９】次に静置重合を実施するには、水、（メ
タ）アクリル酸、（メタ）アクリル酸水溶性塩及びラジ
カル重合開始剤を均一に混合し、以後撹拌や混練を全く
伴わない状態で重合を行い、得られる固形物を粉砕、乾
燥するのである。工業的には上記の均一混合液をバケッ
トコンベヤの中に入れたり、両端に堰を設けたベルト上
に供給したり、チューブ内に供給したり、あるいは任意
の形状を有する容器中に仕込んで４０〜１００℃程度の
温度で０．０３〜５時間混練した後、混合を受けない状
態を保ちつつ重合を進行させる。所定の重合率に達した
樹脂固形物をペレット程度の大きさあるいはそれ以下の
粒径にまで裁断、粉砕し乾燥する。この一連の操作は連
続的に行うのが望ましい。Next, in order to carry out static polymerization, water, (meth) acrylic acid, water-soluble salt of (meth) acrylic acid and radical polymerization initiator are uniformly mixed, and no stirring or kneading is performed thereafter. Polymerization is carried out, and the obtained solid is pulverized and dried. Industrially, the above uniform mixed solution is put in a bucket conveyor, supplied on a belt having weirs at both ends, supplied in a tube, or charged in a container having an arbitrary shape and 40 After kneading at a temperature of about 100 ° C for 0.03 to 5 hours, polymerization is allowed to proceed while keeping no mixing. The resin solid matter having reached a predetermined polymerization rate is cut to a size of a pellet or a particle size smaller than that, pulverized and dried. It is desirable to continuously perform this series of operations.
【００１０】前述したごとき重合法を実施するにあたっ
て、使用される重合開始剤としてはアゾビスイソブチロ
ニトリルのようなアゾニトリル；ｔ−ブチルパーオキシ
ド、クメンハイドロパーオキシド等のアルキルパーオキ
シド；ジ−ｔ−ブチルパーオキシド等のジアルキルパー
オキサイド；アセチルパーオキシド、ラウロイルパーオ
キシド、ステアロイルパーオキシド、ベンゾイルパーオ
キシド等のアミルパーオキシド；ｔ−ブチルパーオキシ
アセテート、ｔ−ブチルパーオキシイソブチレート、ｔ
−ブチルパーオキシピバレート等のパーオキシエステ
ル；メチルエチルケトンパーオキシド、シクロヘキサノ
ンパーオキシド等のケトンパーオキシド、過酸化水素
水、過硫酸アンモニウム、過硫酸カリウム、セリウム塩
等が挙げられる。かかる開始剤の添加量は（メタ）アク
リル酸及び（メタ）アクリル酸水溶性塩の総量に対して
２００〜５０００ｐｐｍ程度が用いられる。In carrying out the above-mentioned polymerization method, the polymerization initiator used is an azonitrile such as azobisisobutyronitrile; an alkyl peroxide such as t-butyl peroxide or cumene hydroperoxide; di- Dialkyl peroxides such as t-butyl peroxide; amyl peroxides such as acetyl peroxide, lauroyl peroxide, stearoyl peroxide, benzoyl peroxide; t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t
Examples include peroxyesters such as butyl peroxypivalate; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; hydrogen peroxide solution; ammonium persulfate; potassium persulfate; and cerium salts. The amount of the initiator added is about 200 to 5000 ppm based on the total amount of (meth) acrylic acid and the water-soluble salt of (meth) acrylic acid.
【００１１】又、逆相懸濁重合時には、好ましくは界面
活性剤を添加して系を安定に保つことが実用的であり、
かかる活性剤としてはポリオキシエチレンアルキルエー
テル、ポリオキシエチレンアシルエステル、ポリオキシ
エチレンソルビタン脂肪酸エステル、ソルビタン脂肪酸
エステル、オキシエチレンオキシプロピレンブロック共
重合体、ショ糖脂肪酸エステル、高級アルコール硫酸エ
ステル塩、アルキルベンゼンスルホン酸塩あるいはポリ
オキシエチレンサルフェート等のノニオン系界面活性
剤、又はアニオン系界面活性剤が単独あるいは併用して
用いられる。更に吸水性能を高度に発揮させる為に、通
常は重合時に水溶性の架橋剤（カルボキシレート基と反
応しうる官能基を２個以上有する架橋剤とは異なる）が
併用される。During the reverse phase suspension polymerization, it is practical to add a surfactant to keep the system stable.
Examples of the activator include polyoxyethylene alkyl ether, polyoxyethylene acyl ester, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, oxyethyleneoxypropylene block copolymer, sucrose fatty acid ester, higher alcohol sulfate ester salt, and alkylbenzene sulfone. A nonionic surfactant such as an acid salt or polyoxyethylene sulfate, or an anionic surfactant is used alone or in combination. Further, in order to exert a high water absorbing property, a water-soluble crosslinking agent (different from a crosslinking agent having two or more functional groups capable of reacting with a carboxylate group) is usually used together during polymerization.
【００１２】該水溶性の架橋剤は（メタ）アクリル酸及
び（メタ）アクリル酸水溶性塩の総量に対して１０〜２
０００ｐｐｍ，好ましくは、５０〜１０００ｐｐｍ用い
られ、かかる水溶性の架橋剤の例示としては、Ｎ，Ｎ’
−メチンビス（メタ）アクリルアミド、Ｎ−メチロール
（メタ）アクリルアミド、（ポリ）エチレングリコール
ジ（メタ）アクリレート、（ポリ）プロピレングリコー
ルジ（メタ）アクリレート、グリセリントリ（メタ）ア
クリレート、グリセリン（メタ）アクリレート、（メ
タ）アクリル酸多価金属塩、トリメチロールプロパント
リ（メタ）アクリレート、トリアリルアミン、トリアリ
ルシアヌレート、トリアリルイソシアヌレート、トリア
リルホスフェート、グリシジル（メタ）アクリレート、
エチレングリコールジグリシジルエーテル、グリセリン
トリ（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、ポリグリセロールポリグリシ
ジルエーテル等が挙げられる。The water-soluble crosslinking agent is 10 to 2 relative to the total amount of (meth) acrylic acid and (meth) acrylic acid water-soluble salt.
000 ppm, preferably 50 to 1000 ppm is used, and as an example of such a water-soluble crosslinking agent, N, N '
-Methinebis (meth) acrylamide, N-methylol (meth) acrylamide, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, glycerin (meth) acrylate, (Meth) acrylic acid polyvalent metal salt, trimethylolpropane tri (meth) acrylate, triallylamine, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, glycidyl (meth) acrylate,
Examples thereof include ethylene glycol diglycidyl ether, glycerin tri (di) glycidyl ether, polyethylene glycol diglycidyl ether, and polyglycerol polyglycidyl ether.
【００１３】又、架橋ポリビニルアルコール変性物から
なる高吸水性樹脂はマレイン酸モノエステルの含量が
０．２〜１５モル％でかつケン化度が７０〜１００モル
％の酢酸ビニル−マレイン酸モノエステル共重合体ケン
化物に含水状態で０．１〜５０Ｍｒａｄｓの電子線又は
放射線を照射するか、または１００℃以上で熱処理する
ことにより得られる。Further, the superabsorbent resin comprising a crosslinked polyvinyl alcohol-modified product has a maleic acid monoester content of 0.2 to 15 mol% and a saponification degree of 70 to 100 mol% vinyl acetate-maleic acid monoester. It can be obtained by irradiating the saponified copolymer with an electron beam or radiation of 0.1 to 50 Mrads in a water-containing state, or by heat treatment at 100 ° C. or higher.
【００１４】本発明においては、上記の如きカルボキシ
レート基を有する高吸水性樹脂の含水率が、３〜５０重
量％であることが必須の条件である。含水率が３重量％
未満では、架橋が効率に行われず、また５０重量％を越
えると、高吸水性樹脂が凝集を起こし、塊となって、均
一な架橋を行うことが困難となる。好ましくは１８〜３
５重量％である。該含水率の高吸水性樹脂を得る方法と
しては、高吸水性樹脂に水を添加する方法あるいは高吸
水性樹脂の製造時に含水させる方法等が挙げられ、高吸
水性樹脂に水を添加する方法としては、高吸水性樹脂に
出来るだけ均一に添加される方法であれば特に制限され
ず、具体的には、噴霧やスチーミングで添加しても良い
し、高吸水性樹脂を含む有機溶媒中に、水を分散させた
有機溶媒を添加してもよい。又、高吸水性樹脂の製造時
に含水させて、水を均一に含む高吸水性樹脂を得る方法
として、好ましくは逆相懸濁重合で得られた水を含む高
吸水性樹脂粉末を共沸脱水で水を留去することにより、
上記水分範囲に調整する方法がある。In the present invention, it is an essential condition that the water content of the super absorbent polymer having a carboxylate group as described above is 3 to 50% by weight. Water content is 3% by weight
If it is less than 50% by weight, the crosslinking is not performed efficiently, and if it exceeds 50% by weight, the superabsorbent polymer agglomerates to form a lump, which makes it difficult to perform uniform crosslinking. Preferably 18 to 3
It is 5% by weight. Examples of the method of obtaining the water-absorbing superabsorbent resin include a method of adding water to the superabsorbent resin, a method of containing water during the production of the superabsorbent resin, and the like, and a method of adding water to the superabsorbent resin. As, as long as it is a method of adding as uniformly as possible to the super absorbent polymer, it is not particularly limited, specifically, it may be added by spraying or steaming, in an organic solvent containing super absorbent resin. In addition, an organic solvent in which water is dispersed may be added. Further, as a method for obtaining a superabsorbent resin which contains water uniformly when it is made to contain water during the production of the superabsorbent resin, preferably the superabsorbent resin powder containing water obtained by reverse phase suspension polymerization is subjected to azeotropic dehydration. By distilling off the water with
There is a method of adjusting the water content within the above range.
【００１５】本発明で高吸水性樹脂に添加して用いられ
るショ糖エステルとしては、ショ糖とステアリン酸、パ
ルミチン酸、ラウリン酸、オレイン酸などの脂肪酸との
モノ、ジまたはトリエステルが挙げられ、具体的には、
ショ糖ステアリン酸エステル、ショ糖パルミチン酸エス
テル、ショ糖ラウリン酸エステル等が用いられる。中で
もＨＬＢ値が１０以下の常温で固体のショ糖ステアリン
酸エステルが好ましい。本発明で用いられるソルビタン
脂肪酸エステルとしては、常温で固体のものが好まし
く、ソルビタンモノパルミテート、ソルビタンモノステ
アレート、ソルビタンセスキステレアート、ソルビタン
トリステアレートなどが挙げられる。中でもＨＬＢ値が
６以下の常温で固体のソルビタンモノステアレートが好
ましい。Examples of the sucrose ester used by adding to the superabsorbent resin in the present invention include mono-, di- or triesters of sucrose and fatty acids such as stearic acid, palmitic acid, lauric acid and oleic acid. ,In particular,
Sucrose stearate, sucrose palmitate, sucrose laurate and the like are used. Among them, sucrose stearate which has a HLB value of 10 or less and is solid at room temperature is preferable. The sorbitan fatty acid ester used in the present invention is preferably solid at room temperature, and examples thereof include sorbitan monopalmitate, sorbitan monostearate, sorbitan sesquistearate, and sorbitan tristearate. Of these, sorbitan monostearate that has a HLB value of 6 or less and is solid at room temperature is preferable.
【００１６】上記のショ糖脂肪酸エステル、又はソルビ
タン脂肪酸エステルの添加量としては特に限定されない
が、水を含まない高吸水性樹脂１００重量部に対して
０．００１〜１０重量部であることが好ましく、より好
ましくは、０．０１〜１重量部である。該エステルの使
用量が０．００１重量部未満では、添加効果に乏しく、
高吸水性樹脂粉末が凝集を起こし、期待する効果が得ら
れない。１０重量部を越えると添加量に見合った効果が
得られないばかりか、吸水量・吸水速度が著しく、低下
するので好ましくない。上記エステルはそれぞれ単独で
の使用は勿論、併用も可能であり、その場合の使用量も
上記と同様である。The amount of the above sucrose fatty acid ester or sorbitan fatty acid ester to be added is not particularly limited, but it is preferably 0.001 to 10 parts by weight with respect to 100 parts by weight of the water-free superabsorbent resin. , And more preferably 0.01 to 1 part by weight. When the amount of the ester used is less than 0.001 part by weight, the effect of addition is poor,
The super absorbent polymer powder causes agglomeration, and the expected effect cannot be obtained. If it exceeds 10 parts by weight, not only the effect commensurate with the addition amount cannot be obtained, but also the water absorption amount and water absorption speed are remarkably lowered, which is not preferable. The above-mentioned esters can be used alone or in combination, and the amount used in that case is also the same as above.
【００１７】本発明で使用されるカルボキシレートと反
応し得る官能基を２個以上有する架橋剤としては、本発
明により改質される高吸水性樹脂中に存在するカルボキ
シレート基、好ましくはこれ以外に水酸基、スルホン
基、アミノ基などと反応し得る官能基を２個以上有する
架橋剤であり、このようなものであれば特に限定される
ことなく使用することができる。前記架橋剤としては、
例えばジグリシジルエーテル系化合物、ハロエポキシ系
化合物、アルデヒド系化合物、イソシアネート系化合物
などが挙げられる。これらのうちでは、例えば（ポリ）
エチレングリコールジグリシジルエーテル、（ポリ）プ
ロピレングリコールジグリシジルエーテル、（ポリ）グ
リセリンジグリシジルエーテルなどのジグリシジルエー
テル系化合物が適しており、これらの中でも、ジエチレ
ングリコールジグリシジルエーテルが高吸水性樹脂中の
カルボキシレート基との反応性から最も適する。The cross-linking agent having two or more functional groups capable of reacting with the carboxylate used in the present invention is a carboxylate group present in the superabsorbent resin modified by the present invention, preferably other than this. Further, it is a cross-linking agent having two or more functional groups capable of reacting with a hydroxyl group, a sulfone group, an amino group and the like, and such a agent can be used without particular limitation. As the cross-linking agent,
For example, diglycidyl ether compounds, haloepoxy compounds, aldehyde compounds, isocyanate compounds and the like can be mentioned. Among these, for example (poly)
Diglycidyl ether compounds such as ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and (poly) glycerin diglycidyl ether are suitable, and among these, diethylene glycol diglycidyl ether is a carboxy in the superabsorbent resin. Most suitable because of its reactivity with the rate group.
【００１８】前記ハロエポキシ系化合物の具体例として
はエピクロルヒドリン、エピブロモヒドリン、α−メチ
ルエポクロルヒドリンなど、アルデヒド系化合物として
は、グルタルアルデヒド、グリオキザールなど、イソシ
アネート系化合物としては２，４−トリレンイジイソシ
アネート、ヘキサメチレンジイソシアネートなどが挙げ
られる。架橋剤の使用量としては、水を含まない高吸水
性樹脂に対して０．００１〜１重量部であることが好ま
しく、より好ましくは０．００５〜０．１重量部であ
る。架橋剤の使用量が０．００１重量部未満では、添加
効果が小さく、また１重量部を越える添加では、過度の
架橋がなされ、吸水量が著しく低下してしまうので好ま
しくない。Specific examples of the haloepoxy-based compound include epichlorohydrin, epibromohydrin, α-methylepochlorohydrin and the like, aldehyde-based compounds such as glutaraldehyde and glyoxal, and isocyanate-based compounds such as 2,4-triphenyl. Examples thereof include rendi diisocyanate and hexamethylene diisocyanate. The amount of the crosslinking agent used is preferably 0.001 to 1 part by weight, and more preferably 0.005 to 0.1 part by weight, based on the water-free superabsorbent resin. If the amount of the cross-linking agent used is less than 0.001 part by weight, the effect of addition will be small, and if it exceeds 1 part by weight, excessive crosslinking will be carried out and the water absorption amount will be significantly reduced, such being undesirable.
【００１９】本発明で用いられる水不溶性無機質粉末と
しては、二酸化ケイ素、酸化アルミニウム、二酸化チタ
ン、タルク、ベントナイト、ゼオライト、その他金属酸
化物が挙げられるが、好ましくは二酸化ケイ素が用いら
れる。又これらの水不溶性無機質粉末は、高吸水性樹脂
表面に吸着されるような微粒子であるほうが良く、好ま
しい粒子径は、２００μｍ以下、特に好ましくは、１０
０μｍ以下である。水不溶性無機質粉末の使用量は水を
含まない高吸水性樹脂に対して０．００５〜２重量部で
あることが好ましく、特に好ましくは０．０５〜１重量
部である。Examples of the water-insoluble inorganic powder used in the present invention include silicon dioxide, aluminum oxide, titanium dioxide, talc, bentonite, zeolite and other metal oxides, but silicon dioxide is preferably used. Further, these water-insoluble inorganic powders are preferably fine particles that can be adsorbed on the surface of the highly water-absorbent resin, and the preferable particle diameter is 200 μm or less, particularly preferably 10 μm.
It is 0 μm or less. The amount of the water-insoluble inorganic powder used is preferably 0.005 to 2 parts by weight, and particularly preferably 0.05 to 1 part by weight, based on the water-free superabsorbent resin.
【００２０】本発明で使用される有機溶剤は、架橋処理
時の架橋反応に対し不活性で、界面活性剤存在下で、カ
ルボキシレート基と反応し得る官能基を２個以上有する
架橋剤を溶解または分散しうるものであれば特に制限さ
れない。具体的にはシクロヘキサン、ｎ−ヘキサンなど
の飽和炭化水素、メタノール、エタノール、イソプロピ
ルアルコールなどの低級アルコール、アセトン、メチル
エチルケトンなどのエーテル類、エチレングリコールモ
ノメチルエーテル、エチレングリコールモノエチルエー
テルなどのエチレングリコールンモノエーテル類などが
挙げられる。有機溶剤の添加量としては、高吸水性樹脂
に十分混合できる量であれば良く、水を含まない高吸水
性樹脂１００重量部に対して２０〜２０００重量部であ
ることが好ましく、より好ましくは４０〜６００重量部
である。The organic solvent used in the present invention is inert to the crosslinking reaction during the crosslinking treatment and dissolves a crosslinking agent having two or more functional groups capable of reacting with the carboxylate group in the presence of a surfactant. Alternatively, it is not particularly limited as long as it can be dispersed. Specifically, saturated hydrocarbons such as cyclohexane and n-hexane, lower alcohols such as methanol, ethanol and isopropyl alcohol, ethers such as acetone and methyl ethyl ketone, ethylene glycol monomethyl ether such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether. Examples thereof include ethers. The amount of the organic solvent added may be an amount that can be sufficiently mixed with the superabsorbent polymer, and is preferably 20 to 2000 parts by weight, more preferably 100 parts by weight of the superabsorbent resin containing no water. 40 to 600 parts by weight.
【００２１】次にかかる高吸水性樹脂を架橋処理する方
法について具体的に説明する。本発明は含水高吸水性樹
脂と、ショ糖脂肪酸エステルおよび又はソルビタン脂肪
酸エステル、水不溶性無機質粉末、カルボキシレート基
と反応し得る官能基を２個以上有する架橋剤及び有機溶
剤と混合した後に、該有機溶剤を留去して架橋処理を行
うことを特徴とするもので、ショ糖脂肪酸エステルおよ
び又はソルビタン脂肪酸エステル、水不溶性無機質粉
末、カルボキシレート基と反応し得る官能基を２個以上
有する架橋剤及び有機溶剤の添加順序については特に制
限されず、どの順序で添加しても、又一括で添加しても
よいが、その混合性の点から以下の順序で添加するのが
好ましい。Next, a method for crosslinking the super absorbent polymer will be specifically described. The present invention comprises a water-containing superabsorbent resin, a sucrose fatty acid ester and / or a sorbitan fatty acid ester, a water-insoluble inorganic powder, a cross-linking agent having two or more functional groups capable of reacting with a carboxylate group, and an organic solvent. Cross-linking treatment is carried out by distilling off an organic solvent, and a sucrose fatty acid ester and / or sorbitan fatty acid ester, a water-insoluble inorganic powder, and a cross-linking agent having two or more functional groups capable of reacting with a carboxylate group. The addition order of the organic solvent and the organic solvent is not particularly limited, and they may be added in any order, or may be added all at once, but from the viewpoint of the mixing property, the following order is preferable.
【００２２】まず含水率が３〜５０重量％に調整された
高吸水性樹脂及び上記のエステルを有機溶媒中に均一に
分散させるか、又は重合反応により得られた高吸水性樹
脂を一部脱溶剤、脱水して上記含水率に調整して、有機
溶剤中に分散させた状態で上記のエステルを均一に分散
させる。これらの操作のときは必要に応じて３０〜１３
０℃程度に加熱することも可能である。次に上記の架橋
剤又は該架橋剤含有の有機溶剤液を添加し、均一に混合
撹拌した後、有機溶剤を留去する。この時、架橋反応を
抑制するため減圧、低温下で行う事が望ましく、その圧
力は１５０〜２５０ｔｏｒｒ、温度は２０〜５０℃の範
囲から好適に選択される。又架橋剤を予め有機溶剤に溶
解又は分散させた有機溶剤液を添加する場合、該溶剤中
の架橋剤の含有量は水を含まない高吸水性樹脂１００重
量部に対して２０〜１００重量部が好ましい。なお該有
機溶剤液中の有機溶剤も前述の有機溶剤の使用量に含ま
れることは言うまでもない。First, the superabsorbent resin whose water content is adjusted to 3 to 50% by weight and the above ester are uniformly dispersed in an organic solvent, or the superabsorbent resin obtained by the polymerization reaction is partially removed. The solvent is dehydrated to adjust the above water content, and the above ester is uniformly dispersed in a state of being dispersed in an organic solvent. During these operations, if necessary, 30 to 13
It is also possible to heat to about 0 ° C. Next, the above-mentioned cross-linking agent or an organic solvent solution containing the cross-linking agent is added, the mixture is uniformly mixed and stirred, and then the organic solvent is distilled off. At this time, in order to suppress the crosslinking reaction, it is desirable to carry out under reduced pressure and low temperature, and the pressure is suitably selected from the range of 150 to 250 torr and the temperature of 20 to 50 ° C. When an organic solvent liquid in which a cross-linking agent is previously dissolved or dispersed in an organic solvent is added, the content of the cross-linking agent in the solvent is 20 to 100 parts by weight based on 100 parts by weight of water-free super absorbent resin. Is preferred. It goes without saying that the organic solvent in the organic solvent liquid is also included in the amount of the organic solvent used.
【００２３】次に水不溶性無機質粉末を添加するのであ
るが、該添加は直接行っても良いが、該粉末の分散性を
考慮すれば、上記架橋剤と同様、予め有機溶剤中で均一
に分散させた後、添加するのが好ましい。なお該有機溶
剤液中の有機溶剤も前述の有機溶剤の添加量に含まれる
ことは言うまでもない。該有機溶剤の留去においては、
有機溶剤の含有量を、水を含まない高吸水性樹脂１００
重量部に対して５重量部以下にすることが望ましい。留
去後は架橋剤の種類により一該に言えないが５０〜１５
０℃、好ましくは７０〜１００℃で３０分〜５時館程度
熱処理を行うのである。その後必要に応じて１０５〜１
５０℃、０．５〜５時間程度の乾燥処理を行い、本発明
の高吸水性樹脂が得られるのである。Next, the water-insoluble inorganic powder is added. The addition may be carried out directly. However, considering the dispersibility of the powder, like the above-mentioned crosslinking agent, it is uniformly dispersed in an organic solvent beforehand. After this, it is preferable to add. It goes without saying that the organic solvent in the organic solvent liquid is also included in the amount of the organic solvent added. In distilling off the organic solvent,
The content of the organic solvent is 100% water-free super absorbent resin.
It is desirable that the amount is 5 parts by weight or less with respect to parts by weight. After the distillation, depending on the type of the cross-linking agent, it cannot be said that it is 50 to 15
Heat treatment is performed at 0 ° C., preferably 70 to 100 ° C. for about 30 minutes to 5 hours. Then, if necessary, 105-1
The superabsorbent resin of the present invention is obtained by performing a drying treatment at 50 ° C for about 0.5 to 5 hours.
【００２４】かかる方法により得られた高吸水性樹脂は
吸収時に「ママコ」を生成せず、しかも荷重下での吸水
性能も優れたもので、紙おむつ、生理用ナプキン等の衛
生用材、土壌の保水剤、種子コーティング剤、止水剤、
増粘剤、結露防止剤、乾燥剤、調湿剤等に広く利用する
ことが出来る。The highly water-absorbent resin obtained by such a method does not form "Mamako" upon absorption, and also has excellent water-absorbing performance under load, such as sanitary materials such as paper diapers and sanitary napkins, and water-retaining soil. Agent, seed coating agent, water blocking agent,
It can be widely used as a thickener, anti-condensation agent, desiccant, humidity control agent and the like.
【００２５】[0025]
【作用】本発明では、特定量の水分を含む高吸水性樹
脂、水不溶性無機質粉末、特定の界面活性剤及び架橋剤
を有機溶剤中で混合後、該有機溶剤を留去して、加熱処
理をしているので、荷重下での吸水力に優れ、「ママ
コ」の生成しない高吸水性樹脂を製造することが出来
る。In the present invention, the superabsorbent resin containing a specific amount of water, the water-insoluble inorganic powder, the specific surfactant and the cross-linking agent are mixed in an organic solvent, and the organic solvent is distilled off, followed by heat treatment. Therefore, it is possible to produce a highly water-absorbent resin that has excellent water absorption under load and does not generate "Mamako".
【００２６】[0026]
【実施例】以下、実施例を挙げて本発明を具体的に説明
する。尚、実施例中、「部」、「％」とあるのは、特に
断りのない限り重量基準である。また高吸水性樹脂の評
価は以下の要領で行った。 (荷重下での吸水力)枝管にコックを付けた５０ｍｌ容量
の枝付ビュレットと内径５５ｍｍφのガラスフィルター
付ロートを内径６ｍｍφのチューブで接続し、ガラスフ
ィルター上面とビュレットの枝管中心位置が同一の高さ
になる様に並べて、放置した。ビュレット中を人工尿で
満たし、ビュレット上部をゴム栓で密栓した。ガラスフ
ィルター付ロートのガラスフィルター上に不織布を介し
て、高吸水性樹脂０．２５ｇを入れ、その上に底面の直
径が５４ｍｍφの円筒状重量４５３ｇのおもりを置き、
ガラスフィルター上の高吸水性樹脂に２０ｇ／cm2の荷
重が加わる様にした。一方該ガラスフィルター付ロート
の先端にチューブ（６ｍｍφ）を付け、該チューブの他
端に５０ｍｌ容量の枝付きビュレットをガラスフィルタ
ー上面とビュレットの枝管中心位置が同一高さになる様
に垂直に置き、人工尿を入れた。この状態で６０分放置
し、高吸水性樹脂の吸水量（ｍｌ／ｇ）を測定した。EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, “part” and “%” are based on weight unless otherwise specified. In addition, the evaluation of the super absorbent polymer was performed according to the following procedure. (Water absorption under load) Connect a 50 ml capacity burette with a branch with a cock to a branch and a funnel with a glass filter with an inner diameter of 55 mmφ with a tube with an inner diameter of 6 mmφ. We arranged them so that they would be at the height of, and left them. The buret was filled with artificial urine, and the top of the buret was sealed with a rubber stopper. On the glass filter of the funnel with a glass filter, put 0.25 g of super absorbent polymer through a non-woven fabric, and put a weight of 453 g of cylindrical weight having a bottom diameter of 54 mmφ on it.
A load of 20 g / cm 2 was applied to the super absorbent resin on the glass filter. On the other hand, a tube (6 mmφ) was attached to the end of the funnel with a glass filter, and a burette with a branch of 50 ml capacity was placed vertically on the other end of the tube so that the upper surface of the glass filter and the center position of the branch pipe of the buret were at the same height. , Put artificial urine. This state was left for 60 minutes, and the water absorption amount (ml / g) of the highly water-absorbent resin was measured.
【００２７】（「ママコ」の有無）上記の荷重下での吸
水力測定直後に、ガラスフィルター上の高吸水性樹脂の
「ママコ」（高吸水性樹脂粒子の膠着）の発生の有無を
目視観察した。尚上記評価に用いた人口尿は尿素２０
ｇ、塩化ナトリウム８．２ｇ、無水硫酸マグネシウム
０．５７ｇ、無水塩化カルシウム０．６４ｇをイオン交
換水１０００ｇに溶解して調製したものを用いた。(Presence or absence of "Mamako") Immediately after measuring the water absorption under the above-mentioned load, the presence or absence of "Mamako" (glue of superabsorbent resin particles) of the superabsorbent resin on the glass filter is visually observed. did. The artificial urine used in the above evaluation was urea 20
g, sodium chloride 8.2 g, anhydrous magnesium sulfate 0.57 g, and anhydrous calcium chloride 0.64 g were dissolved in ion-exchanged water 1000 g, and used.
【００２８】実施例１ 撹拌器、還流冷却器および窒素ガス導入管を付けた５０
０ｍｌセパラブルフラスコにアクリル酸４０ｇを仕込ん
だ後、水５３ｇに純度９５％の水酸化ナトリウム１７．
９ｇを溶解した溶液を撹拌、冷却下に滴下して中和し
た。窒素バブリングを３０分行い、系内の酸素を置換し
た。ついで、あらかじめ窒素バブリングを行った１％過
硫酸アンモニウム水溶液０．４ｇと０．５％Ｎ，Ｎ’−
メチレンビスアクリルアミド水溶液０．２ｇを添加し、
十分混合を行った後、撹拌を停止した。フラスコの６０
℃の温浴に浸し、無撹拌下で重合を開始させたところ、
１０分後に最高８０℃に達した後、内温は６０℃に戻っ
た。更にこの温度に１時間保持してから、室温まで冷却
し重合を停止した。フラスコから内容物を取り出して小
片に裁断し、１００℃で２時間乾燥した後、粉砕機で粉
砕しふるい分けて粒子径３５０〜７４μｍの高吸水性樹
脂粒子（Ａ）を得た。この粒子（Ａ）２４ｇを双腕型ニ
ーダ反応器に仕込み、撹拌下に水１６ｇを手動型霧吹き
機をもちいて噴霧して、含水率４０重量％の高吸水性樹
脂とした。更に、ｎ−ヘキサン２０ｇを加えた後、ソル
ビタンモノステアレート０．００８ｇ、微粉末ＳｉＯ2
（日本シリカ工業（株）製、商品名「ニップシールＬ
ｐ」（平均粒径９μｍ））０．４ｇとジエチレングリコ
ールジグリシジルエーテル０．００４ｇを加え、３０分
混合した。その後、撹拌しながら、減圧下に４０℃に加
熱してｎ−ヘキサンを留去した。その後、常圧に戻し７
０℃に加熱して、１時間架橋反応を行った。その後、開
放状態で１２０℃で２時間加熱して乾燥し、本発明の高
吸水性樹脂を得た。Example 1 50 equipped with a stirrer, a reflux condenser and a nitrogen gas introducing tube
After charging 40 g of acrylic acid in a 0 ml separable flask, sodium hydroxide having a purity of 95% was added to 53 g of water.
The solution in which 9 g was dissolved was added dropwise with stirring and cooling to neutralize. Nitrogen bubbling was performed for 30 minutes to replace oxygen in the system. Then, 0.4 g of a 1% ammonium persulfate aqueous solution which had been subjected to nitrogen bubbling in advance and 0.5% N, N'-
Add 0.2 g of methylenebisacrylamide aqueous solution,
After sufficiently mixing, stirring was stopped. 60 in a flask
When immersed in a warm bath at ℃ and started the polymerization without stirring,
After reaching a maximum of 80 ° C after 10 minutes, the internal temperature returned to 60 ° C. Further, this temperature was maintained for 1 hour and then cooled to room temperature to terminate the polymerization. The content was taken out of the flask, cut into small pieces, dried at 100 ° C. for 2 hours, pulverized with a pulverizer and sieved to obtain superabsorbent resin particles (A) having a particle diameter of 350 to 74 μm. 24 g of the particles (A) were charged into a double-arm kneader reactor, and 16 g of water was sprayed with stirring using a manual sprayer to give a highly water-absorbent resin having a water content of 40% by weight. Further, after adding 20 g of n-hexane, 0.008 g of sorbitan monostearate and SiO 2 fine powder
(Manufactured by Nippon Silica Industry Co., Ltd., trade name "Nipseal L"
p ”(average particle size 9 μm)) and diethylene glycol diglycidyl ether 0.004 g were added and mixed for 30 minutes. Then, while stirring, the mixture was heated to 40 ° C. under reduced pressure to distill off n-hexane. Then return to normal pressure 7
The mixture was heated to 0 ° C. to carry out a crosslinking reaction for 1 hour. Then, it was heated in an open state at 120 ° C. for 2 hours and dried to obtain a highly water-absorbent resin of the present invention.
【００２９】比較例１ 実施例１において、噴霧添加する水量を０．７４ｇとし
て、高吸水性樹脂の含水率を２重量％とした以外は、実
施例１と同様にして、高吸水性樹脂を得た。 比較例２ 実施例１において、噴霧添加する水量を３６ｇとして、
高吸水性樹脂の含水率を６０重量％とした以外は、実施
例１と同様にして、高吸水性樹脂を得た。Comparative Example 1 A superabsorbent resin was prepared in the same manner as in Example 1 except that the amount of water added by spraying was 0.74 g and the water content of the superabsorbent resin was 2% by weight. Obtained. Comparative Example 2 In Example 1, the amount of water added by spraying was 36 g,
A super absorbent polymer was obtained in the same manner as in Example 1 except that the water content of the super absorbent resin was 60% by weight.
【００３０】実施例２ 実施例１において、架橋剤を二官能脂環式エポキシ化合
物（ダイセル化学工業（株）製、商品名「セロキサイド
２０２１」）に換えた以外は、実施例１と同様にして、
高吸水性樹脂を得た。Example 2 In the same manner as in Example 1, except that the bifunctional alicyclic epoxy compound (manufactured by Daicel Chemical Industries, Ltd., trade name “Celoxide 2021”) was used as the crosslinking agent. ,
A super absorbent resin was obtained.
【００３１】比較例３ 実施例１において、ｎ−ヘキサンを用いずに、架橋剤と
してジエチレングリコールジグリシジルエーテル０．０
０４ｇを水８ｇ溶解して、噴霧しながら添加した以外
は、実施例１と同様にして、高吸水性樹脂を得た。Comparative Example 3 The procedure of Example 1 was repeated except that n-hexane was not used, and diethylene glycol diglycidyl ether 0.0 was used as a crosslinking agent.
A highly water-absorbent resin was obtained in the same manner as in Example 1 except that 04 g of water was dissolved in 8 g of water and added while spraying.
【００３２】比較例４ 撹拌器、還流冷却器および窒素ガス導入管を付けたセパ
ラブルフラスコ（フラスコＡ）にシクロヘキサン８００
ｍｌ、保護コロイド剤として、ショ糖脂肪酸エステル
（第一工業製薬（株）製、商品名「ＤＫエステルＦ−７
０」）０．７８ｇとソルビタンモノステアレート０．７
８ｇを仕込み、窒素バブリングを行って、系内の溶存酸
素を置換した。別のセパラブルフラスコ（フラスコＢ）
に８０％アクリル酸水溶液２６０ｇを仕込んだ後、２８
％の水酸化ナトリウム水溶液３１０ｇを、冷却下に徐々
に滴下して中和した。ついで、５％Ｎ，Ｎ’−メチレン
ビスアクリルアミド水溶液８ｇと１０％過硫酸アンモニ
ウム水溶液４ｇを加え、撹拌しながら窒素バブリングを
行い、溶存酸素を置換した。フラスコＡを７３℃に昇温
した後、フラスコＢの溶液を１．５時間かけて滴下し
た。重合時の撹拌器の回転数は、３５０ｒｐｍに設定し
た。その後、ジャケットを９５℃に保ち、シクロヘキサ
ンと水を共沸させ、水２３０ｍｌを留去した。ここで、
高吸水性樹脂１００重量部に対して３７．２重量部の水
を含み（含水率２７重量％）、ショ糖脂肪酸エステル
（第一工業製薬（株）製、商品名「ＤＫエステルＦ−７
０」）とソルビタンモノステアレートの混合物０．００
６重量部とシクロヘキサン２４３重量部の混じった高吸
水性樹脂２５６．５ｇを含む高吸水性樹脂のシクロヘキ
サン分散液（分散液Ｂ）を得た。この分散液Ｂと微粉末
ＳｉＯ2（日本シリカ工業（株）製、商品名「ニップシ
ールＬｐ」（平均粒径９μｍ））２．５６ｇを１２０℃
で３時間加熱して、水およびシクロヘキサンを留去し
て、乾燥した高吸水性樹脂を得た。Comparative Example 4 Cyclohexane 800 was placed in a separable flask (flask A) equipped with a stirrer, a reflux condenser and a nitrogen gas inlet tube.
ml, as a protective colloid agent, sucrose fatty acid ester (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name "DK Ester F-7"
0 ") 0.78 g and sorbitan monostearate 0.7
8 g was charged and nitrogen bubbling was performed to replace the dissolved oxygen in the system. Another separable flask (flask B)
After charging 260 g of 80% acrylic acid aqueous solution into the
% Sodium hydroxide aqueous solution (310 g) was gradually added dropwise under cooling to neutralize. Then, 8 g of a 5% N, N′-methylenebisacrylamide aqueous solution and 4 g of a 10% ammonium persulfate aqueous solution were added, and nitrogen bubbling was performed while stirring to replace the dissolved oxygen. After the temperature of Flask A was raised to 73 ° C., the solution of Flask B was added dropwise over 1.5 hours. The rotation speed of the stirrer during the polymerization was set to 350 rpm. Then, the jacket was kept at 95 ° C. to azeotrope cyclohexane and water, and 230 ml of water was distilled off. here,
Sucrose fatty acid ester (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name "DK Ester F-7", containing 37.2 parts by weight of water per 100 parts by weight of super absorbent polymer (water content 27% by weight).
0 ") and sorbitan monostearate 0.00
A cyclohexane dispersion liquid (dispersion liquid B) of a super absorbent resin containing 256.5 g of a super absorbent resin in which 6 parts by weight and 243 parts by weight of cyclohexane were mixed was obtained. 2.56 g of this dispersion B and fine powder SiO 2 (trade name “Nipseal Lp” (average particle size 9 μm), manufactured by Nippon Silica Industry Co., Ltd.) are added at 120 ° C.
After heating for 3 hours, water and cyclohexane were distilled off to obtain a dried super absorbent polymer.
【００３３】実施例３ 比較例４で得た分散液Ｂに対し、架橋剤として、二官能
脂環式エポキシ化合物（ダイセル化学工業（株）製、商
品名「セロキサイド２０２１」）０．０３８５ｇを添加
し、十分撹拌した。その後減圧下、４０℃に加熱してシ
クロヘキサンを留去した。常圧に戻した後、７０℃で１
時間加熱して架橋反応を行った後、更に１２０℃に昇温
して、３時間保持して乾燥し、本発明の高吸水性樹脂を
得た。Example 3 To the dispersion B obtained in Comparative Example 4, 0.0385 g of a bifunctional alicyclic epoxy compound (manufactured by Daicel Chemical Industries, Ltd., trade name "Celoxide 2021") was added as a crosslinking agent. And stirred well. Then, the mixture was heated to 40 ° C. under reduced pressure to remove cyclohexane. After returning to normal pressure, 1 at 70 ℃
After heating for a period of time to carry out a crosslinking reaction, the temperature was further raised to 120 ° C., and the temperature was kept for 3 hours and dried to obtain a super absorbent polymer of the present invention.
【００３４】実施例４ 実施例３で分散液Ｂを得る前の、高吸水性樹脂の含水率
を２０％に調整した以外は実施例３と同様にして本発明
の高吸水性樹脂を得た。上記実施例及び比較例で得られ
たＳＡＰについての、荷重下での吸水力及び「ママコ」
の有無の評価結果を表１に示す。Example 4 A highly water-absorbent resin of the present invention was obtained in the same manner as in Example 3 except that the water content of the highly water-absorbent resin before the dispersion B was obtained in Example 3 was adjusted to 20%. . Regarding the SAPs obtained in the above Examples and Comparative Examples, the water absorption capacity under load and "Mamako"
Table 1 shows the evaluation results of the presence or absence of.
【００３５】[0035]
【表１】 含水率＊ 架橋剤＊＊ 荷重下での吸水力 ママコの有無 重量％ （ｍｌ／ｇ） 実施例１ ４０ ａ ２８ なし 実施例２ ４０ ｂ ３０ なし 実施例３ ２７ ｂ ３２ なし実施例４ ２０ ａ ３４ なし 比較例１ ２ ａ ５ あり 比較例２ ６０ ａ １０ あり 比較例３ ４０ ａ １４ あり比較例４ ２７ ａ １２ あり ＊界面活性剤、架橋剤、水不溶性無機質粉末を加える前の高吸水性樹脂の含水率 ＊＊架橋剤の略称は以下の通り ａ：ジエチレングリコールジグリシジルエーテル ｂ：二官能脂環式エポキシ化合物（ダイセル化学工業（株）製、商品名「セロ キサイド２０２１」）[Table 1] Moisture content * Crosslinking agent ** Water absorption under load Presence / absence of Mamako (% / ml) Example 1 40 a 28 None Example 2 40 b 30 None Example 3 27 b 32 None Example 4 20 a 34 None Comparative Example 1 2 a 5 Yes Comparative Example 2 60 a 10 Yes Comparative Example 3 40 a 14 Yes Comparative Example 4 27 a 12 Yes * High before adding surfactant, cross-linking agent, water-insoluble inorganic powder Water content of water-absorbent resin ** Abbreviations of cross-linking agents are as follows: a: Diethylene glycol diglycidyl ether b: Bifunctional alicyclic epoxy compound (manufactured by Daicel Chemical Industries, Ltd., trade name "Ceroxide 2021")
【００３６】[0036]
【発明の効果】本発明では、特定量の水分を含む高吸水
性樹脂、水不溶性無機質粉末、特定の界面活性剤及び架
橋剤を有機溶剤中で混合後、該有機溶剤を留去して、加
熱処理をしているので、荷重下での吸水力に優れ、「マ
マコ」の生成しない高吸水性樹脂を製造することが出来
る。INDUSTRIAL APPLICABILITY In the present invention, a highly water-absorbent resin containing a specific amount of water, a water-insoluble inorganic powder, a specific surfactant and a crosslinking agent are mixed in an organic solvent, and then the organic solvent is distilled off, Since it is heat-treated, it is possible to produce a highly water-absorbent resin that has excellent water absorption under load and does not generate "Mamako".
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成７年１２月２５日[Submission date] December 25, 1995
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００３５[Correction target item name] 0035
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００３５】[0035]
【表１】 含水率＊ 架橋剤＊＊ 荷重下での吸水力 ママコの有無 重量％ （ｍｌ／ｇ） 実施例１ ４０ ａ ３０ なし 実施例２ ４０ ｂ ３２ なし 実施例３ ２７ ｂ ３４ なし 実施例４ ２０ ａ ３６ なし 比較例１ ２ ａ ９ あり 比較例２ ６０ ａ １４ あり 比較例３ ４０ ａ １８ あり 比較例４ ２７ なし １３ あり ＊界面活性剤、架橋剤、水不溶性無機質粉末を加える前の高吸水性樹脂の含水率 ＊＊架橋剤の略称は以下の通り ａ：ジエチレングリコールジグリシジルエーテル ｂ：二官能脂環式エポキシ化合物（ダイセル化学工業（株）製、商品名「セロ キサイド２０２１」）[Table 1] Moisture content * Crosslinking agent ** Water absorption under load Presence / absence of Momako (% / ml) Example 1 40 a 30 None Example 2 40 b 32 None Example 3 27 b 34 None Example 4 20 a 36 None Comparative Example 1 2 a 9 Yes Comparative Example 2 60 a 14 Yes Comparative Example 3 40 a 18 Yes Comparative Example 4 27 No 13 Yes * Water content of super absorbent resin before adding surfactant, cross-linking agent and water-insoluble inorganic powder ** Abbreviation of cross-linking agent is as follows: a: Diethylene glycol diglycidyl ether b: Bifunctional alicyclic epoxy compound (Daicel Chemical Industry Co., Ltd., trade name "Celoxide 2021")
Claims (10)
シレート基を有する高吸水性樹脂と、ショ糖脂肪酸エス
テルおよび／またはソルビタン脂肪酸エステル、カルボ
キシレート基と反応しうる官能基を２個以上有する架橋
剤、及び水不溶性無機質粉末を有機溶剤の存在下で混合
した後、有機溶剤を留去して、次いで加熱して架橋処理
を行うことを特徴とする高吸水性樹脂の製造法。1. A highly water-absorbent resin having a water content of 3 to 50% by weight and having a carboxylate group, sucrose fatty acid ester and / or sorbitan fatty acid ester, and two or more functional groups capable of reacting with a carboxylate group. A method for producing a highly water-absorbent resin, which comprises mixing the crosslinking agent and the water-insoluble inorganic powder in the presence of an organic solvent, distilling off the organic solvent, and then heating to carry out a crosslinking treatment.
脂がポリアクリル酸塩架橋体あるいは架橋ポリビニルア
ルコール変性物であることを特徴とする請求項１記載の
高吸水性樹脂の製造法。2. The method for producing a superabsorbent resin according to claim 1, wherein the superabsorbent resin having a carboxylate group is a polyacrylate crosslinked product or a crosslinked polyvinyl alcohol-modified product.
脂の含水率が１８〜３５重量％であることを特徴とする
請求項１又は２記載の高吸水性樹脂の製造法。3. The method for producing a superabsorbent resin according to claim 1, wherein the superabsorbent resin having a carboxylate group has a water content of 18 to 35% by weight.
ルビタン脂肪酸エステルの添加量が、水を含まない高吸
水性樹脂１００重量部に対して０．００１〜１０重量部
であることを特徴とする請求項１記載の高吸水性樹脂の
製造法。4. The addition amount of sucrose fatty acid ester and / or sorbitan fatty acid ester is 0.001 to 10 parts by weight with respect to 100 parts by weight of a water-free superabsorbent resin. 1. The method for producing the super absorbent polymer according to 1.
を２個以上有する架橋剤が、ジエチレングリコールジグ
リシジルエーテルあるいは二官能脂環式エポキシ化合物
であることを特徴とする請求項１記載の高吸水性樹脂の
製造法。5. The superabsorbent polymer according to claim 1, wherein the crosslinking agent having two or more functional groups capable of reacting with a carboxylate group is diethylene glycol diglycidyl ether or a bifunctional alicyclic epoxy compound. Resin manufacturing method.
を２個以上有する架橋剤の添加量が、水を含まない高吸
水性樹脂１００重量部に対して、０．００１〜１重量部
であることを特徴とする請求項１又は５記載の高吸水性
樹脂の製造法。6. The addition amount of a crosslinking agent having two or more functional groups capable of reacting with a carboxylate group is 0.001 to 1 part by weight based on 100 parts by weight of a water-free superabsorbent resin. The method for producing a highly water-absorbent resin according to claim 1 or 5, wherein
ることを特徴とする請求項１記載の高吸水性樹脂の製造
方法。7. The method for producing a highly water-absorbent resin according to claim 1, wherein the water-insoluble inorganic powder is silicon dioxide.
まない高吸水性樹脂１００重量部に対して０．００５〜
２重量部であることを特徴とする請求項１又は７記載の
高吸水性樹脂の製造方法。8. The amount of the water-insoluble inorganic powder added is 0.005 to 100 parts by weight of water-free superabsorbent resin.
It is 2 weight part, The manufacturing method of the super absorbent resin of Claim 1 or 7 characterized by the above-mentioned.
ｍ以下であることを特徴とする請求項１、７又は８記載
の高吸水性樹脂の製造方法。9. The particle size of the water-insoluble inorganic powder is 200 μm.
It is m or less, The manufacturing method of the super absorbent resin of Claim 1, 7 or 8 characterized by the above-mentioned.
吸水性樹脂１００重量部に対して、２０〜２０００重量
部であることを特徴とする請求項１記載の高吸水性樹脂
の製造法。10. The production of a super absorbent polymer according to claim 1, wherein the added amount of the organic solvent is 20 to 2000 parts by weight with respect to 100 parts by weight of the super absorbent polymer containing no water. Law.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33106494A JPH08157531A (en) | 1994-12-07 | 1994-12-07 | Production of highly water-absorbing resin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33106494A JPH08157531A (en) | 1994-12-07 | 1994-12-07 | Production of highly water-absorbing resin |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08157531A true JPH08157531A (en) | 1996-06-18 |
Family
ID=18239461
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33106494A Pending JPH08157531A (en) | 1994-12-07 | 1994-12-07 | Production of highly water-absorbing resin |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08157531A (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000077093A1 (en) * | 1999-06-15 | 2000-12-21 | Sumitomo Seika Chemicals Co., Ltd. | Carboxylated polymer composition |
| JP2005179384A (en) * | 2003-12-16 | 2005-07-07 | Asahi Kasei Chemicals Corp | Method for producing water absorbing resin |
| US6933356B2 (en) | 2001-04-05 | 2005-08-23 | Sumitomo Seika Chemicals Co., Ltd. | Particles of carboxylated polymer |
| EP1325777A4 (en) * | 2000-07-18 | 2006-05-24 | Sanyo Chemical Ind Ltd | Absorbents and process for producing the same, absorbable constructs and absorbable articles |
| JP2006526691A (en) * | 2003-04-25 | 2006-11-24 | ストックハウゼン・インコーポレイテッド | Super absorbent polymer with high water permeability |
| WO2008015980A1 (en) * | 2006-08-04 | 2008-02-07 | Sumitomo Seika Chemicals Co., Ltd. | Water-absorbable resin particle, method for production thereof, and absorber material using the same |
| KR100844181B1 (en) * | 2007-02-15 | 2008-07-04 | 애경정밀화학 주식회사 | Composition for manufacturing a carboxylic group containing polymer and a polymer prepared thereof |
| JP4768613B2 (en) * | 2003-07-28 | 2011-09-07 | ビーエーエスエフ ソシエタス・ヨーロピア | Method for post-crosslinking hydrogels with bicyclic amide acetals |
| JP2011241253A (en) * | 2010-05-14 | 2011-12-01 | Sanyo Chem Ind Ltd | Water-soluble resin particle |
| JP2012041439A (en) * | 2010-08-19 | 2012-03-01 | San-Dia Polymer Ltd | Absorbing resin particle and absorbent article |
| JP2013203842A (en) * | 2012-03-28 | 2013-10-07 | San-Dia Polymer Ltd | Absorptive resin particle and absorber and absorptive article containing the same |
| WO2019117511A1 (en) | 2017-12-11 | 2019-06-20 | 주식회사 엘지화학 | Superabsorbent polymer and preparation method therefor |
| CN111448241A (en) * | 2017-12-11 | 2020-07-24 | 株式会社Lg化学 | Superabsorbent polymer composition and method of making the same |
| US11466131B2 (en) | 2018-11-13 | 2022-10-11 | Lg Chem, Ltd. | Superabsorbent polymer and preparation method thereof |
| US11613613B2 (en) | 2017-12-11 | 2023-03-28 | Lg Chem, Ltd. | Superabsorbent polymer composition and method for preparing the same |
-
1994
- 1994-12-07 JP JP33106494A patent/JPH08157531A/en active Pending
Cited By (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6869994B1 (en) | 1999-06-15 | 2005-03-22 | Sumitomo Seika Chemicals Co., Ltd. | Carboxylated polymer composition |
| WO2000077093A1 (en) * | 1999-06-15 | 2000-12-21 | Sumitomo Seika Chemicals Co., Ltd. | Carboxylated polymer composition |
| EP1325777A4 (en) * | 2000-07-18 | 2006-05-24 | Sanyo Chemical Ind Ltd | Absorbents and process for producing the same, absorbable constructs and absorbable articles |
| US6933356B2 (en) | 2001-04-05 | 2005-08-23 | Sumitomo Seika Chemicals Co., Ltd. | Particles of carboxylated polymer |
| JP2006526691A (en) * | 2003-04-25 | 2006-11-24 | ストックハウゼン・インコーポレイテッド | Super absorbent polymer with high water permeability |
| JP4768613B2 (en) * | 2003-07-28 | 2011-09-07 | ビーエーエスエフ ソシエタス・ヨーロピア | Method for post-crosslinking hydrogels with bicyclic amide acetals |
| JP2005179384A (en) * | 2003-12-16 | 2005-07-07 | Asahi Kasei Chemicals Corp | Method for producing water absorbing resin |
| JP5289955B2 (en) * | 2006-08-04 | 2013-09-11 | 住友精化株式会社 | Water-absorbent resin particles, method for producing the same, and absorbent body using the same |
| WO2008015980A1 (en) * | 2006-08-04 | 2008-02-07 | Sumitomo Seika Chemicals Co., Ltd. | Water-absorbable resin particle, method for production thereof, and absorber material using the same |
| KR100844181B1 (en) * | 2007-02-15 | 2008-07-04 | 애경정밀화학 주식회사 | Composition for manufacturing a carboxylic group containing polymer and a polymer prepared thereof |
| JP2011241253A (en) * | 2010-05-14 | 2011-12-01 | Sanyo Chem Ind Ltd | Water-soluble resin particle |
| JP2012041439A (en) * | 2010-08-19 | 2012-03-01 | San-Dia Polymer Ltd | Absorbing resin particle and absorbent article |
| JP2013203842A (en) * | 2012-03-28 | 2013-10-07 | San-Dia Polymer Ltd | Absorptive resin particle and absorber and absorptive article containing the same |
| WO2019117511A1 (en) | 2017-12-11 | 2019-06-20 | 주식회사 엘지화학 | Superabsorbent polymer and preparation method therefor |
| CN111448241A (en) * | 2017-12-11 | 2020-07-24 | 株式会社Lg化学 | Superabsorbent polymer composition and method of making the same |
| JP2021504519A (en) * | 2017-12-11 | 2021-02-15 | エルジー・ケム・リミテッド | Highly absorbent resin and its manufacturing method |
| US11613613B2 (en) | 2017-12-11 | 2023-03-28 | Lg Chem, Ltd. | Superabsorbent polymer composition and method for preparing the same |
| CN111448241B (en) * | 2017-12-11 | 2024-03-01 | 株式会社Lg化学 | Superabsorbent polymer composition and method of making the same |
| US11931720B2 (en) | 2017-12-11 | 2024-03-19 | Lg Chem, Ltd. | Superabsorbent polymer composition and method for preparing the same |
| US11466131B2 (en) | 2018-11-13 | 2022-10-11 | Lg Chem, Ltd. | Superabsorbent polymer and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7179862B2 (en) | Powdery, cross-linked absorbent polymers method for the production thereof and their use | |
| US10207250B2 (en) | Poly(meth)acrylic acid (salt)-based particulate absorbent | |
| EP0999238B1 (en) | Water-absorbing agent and production process therefor | |
| EP0878488B2 (en) | Method for production of hydrophilic resin | |
| JPH08157531A (en) | Production of highly water-absorbing resin | |
| JP2877255B2 (en) | Manufacturing method of water absorbent resin with excellent durability | |
| JP2013100529A (en) | Production process for water-absorbent resin | |
| JPH07242709A (en) | Preparation of water-absorbent resin | |
| JPH0615574B2 (en) | Method for producing water absorbent resin | |
| JPH0625209B2 (en) | Water absorbent resin and method for producing the same | |
| JPH0826085B2 (en) | Method for producing water-absorbent resin having excellent durability | |
| JPH0639487B2 (en) | Super absorbent resin manufacturing method | |
| JPH03195713A (en) | Production of polymer having high water absorption | |
| JPH08253597A (en) | Method for granulating highly water-absorptive resin | |
| JPH08157606A (en) | Production of highly water-absorbing resin | |
| JPH0967522A (en) | Production of water-absorbing resin | |
| JPH06200046A (en) | Preparation of modified highly water-absorptive resin and resin | |
| JPH0655838B2 (en) | Surface treatment method for water absorbent resin | |
| JPH09194598A (en) | Granulation of high water absorbing resin | |
| JPH11199602A (en) | Water absorbing polymer and its production | |
| JPH0655777B2 (en) | Water absorbent resin and method for producing the same | |
| JP3515679B2 (en) | Water absorbent resin and manufacturing method | |
| JP3439230B2 (en) | Method for producing water absorbent resin | |
| JP6555832B2 (en) | Method for producing aqueous liquid absorbent resin | |
| JP3059236B2 (en) | Granulation of superabsorbent polymer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Effective date: 20040420 Free format text: JAPANESE INTERMEDIATE CODE: A131 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20040817 |