JPH0321562B2 - - Google Patents
Info
- Publication number
- JPH0321562B2 JPH0321562B2 JP58164871A JP16487183A JPH0321562B2 JP H0321562 B2 JPH0321562 B2 JP H0321562B2 JP 58164871 A JP58164871 A JP 58164871A JP 16487183 A JP16487183 A JP 16487183A JP H0321562 B2 JPH0321562 B2 JP H0321562B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- aqueous solution
- component
- hydrogen atom
- polymerization reaction
- 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 - Lifetime
Links
- 229920005989 resin Polymers 0.000 claims description 42
- 239000011347 resin Substances 0.000 claims description 42
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 39
- 239000007864 aqueous solution Substances 0.000 claims description 38
- 239000000178 monomer Substances 0.000 claims description 38
- 238000006116 polymerization reaction Methods 0.000 claims description 30
- -1 divinyl compound Chemical class 0.000 claims description 12
- 125000004435 hydrogen atom Chemical group [H]* 0.000 claims description 10
- 239000002250 absorbent Substances 0.000 claims description 9
- 230000002745 absorbent Effects 0.000 claims description 8
- 229910052783 alkali metal Inorganic materials 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 150000001875 compounds Chemical class 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 6
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 6
- 239000003505 polymerization initiator Substances 0.000 claims description 6
- KAKZBPTYRLMSJV-UHFFFAOYSA-N vinyl-ethylene Natural products C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 claims description 6
- 150000001340 alkali metals Chemical group 0.000 claims description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-O ammonium group Chemical group [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 4
- 230000008016 vaporization Effects 0.000 claims description 4
- TURITJIWSQEMDB-UHFFFAOYSA-N 2-methyl-n-[(2-methylprop-2-enoylamino)methyl]prop-2-enamide Chemical compound CC(=C)C(=O)NCNC(=O)C(C)=C TURITJIWSQEMDB-UHFFFAOYSA-N 0.000 claims description 3
- ZIUHHBKFKCYYJD-UHFFFAOYSA-N n,n'-methylenebisacrylamide Chemical compound C=CC(=O)NCNC(=O)C=C ZIUHHBKFKCYYJD-UHFFFAOYSA-N 0.000 claims description 3
- 239000011837 N,N-methylenebisacrylamide Substances 0.000 claims description 2
- 125000002947 alkylene group Chemical group 0.000 claims description 2
- 125000004432 carbon atom Chemical group C* 0.000 claims description 2
- 125000001841 imino group Chemical group [H]N=* 0.000 claims description 2
- 125000004430 oxygen atom Chemical group O* 0.000 claims description 2
- 238000010521 absorption reaction Methods 0.000 description 31
- 239000003792 electrolyte Substances 0.000 description 15
- 229920000642 polymer Polymers 0.000 description 15
- 239000003999 initiator Substances 0.000 description 13
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 12
- 238000006243 chemical reaction Methods 0.000 description 9
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 8
- 239000003795 chemical substances by application Substances 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 239000000843 powder Substances 0.000 description 8
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 239000008151 electrolyte solution Substances 0.000 description 5
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 239000011259 mixed solution Substances 0.000 description 4
- IRLPACMLTUPBCL-KQYNXXCUSA-N 5'-adenylyl sulfate Chemical compound C1=NC=2C(N)=NC=NC=2N1[C@@H]1O[C@H](COP(O)(=O)OS(O)(=O)=O)[C@@H](O)[C@H]1O IRLPACMLTUPBCL-KQYNXXCUSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000004132 cross linking Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 238000006386 neutralization reaction Methods 0.000 description 3
- 229920000058 polyacrylate Polymers 0.000 description 3
- 238000009834 vaporization Methods 0.000 description 3
- XHZPRMZZQOIPDS-UHFFFAOYSA-N 2-Methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid Chemical compound OS(=O)(=O)CC(C)(C)NC(=O)C=C XHZPRMZZQOIPDS-UHFFFAOYSA-N 0.000 description 2
- QMYCJCOPYOPWTI-UHFFFAOYSA-N 2-[(1-amino-1-imino-2-methylpropan-2-yl)diazenyl]-2-methylpropanimidamide;hydron;chloride Chemical compound Cl.NC(=N)C(C)(C)N=NC(C)(C)C(N)=N QMYCJCOPYOPWTI-UHFFFAOYSA-N 0.000 description 2
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 2
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 2
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 2
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 2
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 2
- 229920002472 Starch Polymers 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 150000003863 ammonium salts Chemical class 0.000 description 2
- 239000001768 carboxy methyl cellulose Substances 0.000 description 2
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 2
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 2
- 239000000701 coagulant Substances 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 239000003431 cross linking reagent Substances 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229920000578 graft copolymer Polymers 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229920002239 polyacrylonitrile Polymers 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 239000012966 redox initiator Substances 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000008107 starch Substances 0.000 description 2
- 235000019698 starch Nutrition 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- 210000002700 urine Anatomy 0.000 description 2
- AOSFMYBATFLTAQ-UHFFFAOYSA-N 1-amino-3-(benzimidazol-1-yl)propan-2-ol Chemical compound C1=CC=C2N(CC(O)CN)C=NC2=C1 AOSFMYBATFLTAQ-UHFFFAOYSA-N 0.000 description 1
- VILCJCGEZXAXTO-UHFFFAOYSA-N 2,2,2-tetramine Chemical compound NCCNCCNCCN VILCJCGEZXAXTO-UHFFFAOYSA-N 0.000 description 1
- XSOYAYUIVRZUMZ-UHFFFAOYSA-N 2,4-dimethyl-3-oxopent-4-ene-1-sulfonic acid Chemical compound OS(=O)(=O)CC(C)C(=O)C(C)=C XSOYAYUIVRZUMZ-UHFFFAOYSA-N 0.000 description 1
- PRAMZQXXPOLCIY-UHFFFAOYSA-N 2-(2-methylprop-2-enoyloxy)ethanesulfonic acid Chemical compound CC(=C)C(=O)OCCS(O)(=O)=O PRAMZQXXPOLCIY-UHFFFAOYSA-N 0.000 description 1
- JBIUHXCCAZFBCL-UHFFFAOYSA-N 2-(2-methylprop-2-enoyloxy)propane-1-sulfonic acid Chemical compound OS(=O)(=O)CC(C)OC(=O)C(C)=C JBIUHXCCAZFBCL-UHFFFAOYSA-N 0.000 description 1
- 229920000536 2-Acrylamido-2-methylpropane sulfonic acid Polymers 0.000 description 1
- VSSGDAWBDKMCMI-UHFFFAOYSA-N 2-methyl-2-(2-methylprop-2-enoylamino)propane-1-sulfonic acid Chemical compound CC(=C)C(=O)NC(C)(C)CS(O)(=O)=O VSSGDAWBDKMCMI-UHFFFAOYSA-N 0.000 description 1
- VYVCCAVYYHVSFZ-UHFFFAOYSA-N 2-methyl-3-oxopent-4-ene-1-sulfonic acid Chemical compound OS(=O)(=O)CC(C)C(=O)C=C VYVCCAVYYHVSFZ-UHFFFAOYSA-N 0.000 description 1
- GQTFHSAAODFMHB-UHFFFAOYSA-N 2-prop-2-enoyloxyethanesulfonic acid Chemical compound OS(=O)(=O)CCOC(=O)C=C GQTFHSAAODFMHB-UHFFFAOYSA-N 0.000 description 1
- MJIFFWRTVONWNO-UHFFFAOYSA-N 3-oxopent-4-ene-1-sulfonic acid Chemical compound OS(=O)(=O)CCC(=O)C=C MJIFFWRTVONWNO-UHFFFAOYSA-N 0.000 description 1
- VFXXTYGQYWRHJP-UHFFFAOYSA-N 4,4'-azobis(4-cyanopentanoic acid) Chemical compound OC(=O)CCC(C)(C#N)N=NC(C)(CCC(O)=O)C#N VFXXTYGQYWRHJP-UHFFFAOYSA-N 0.000 description 1
- SVYPQURSUBDSIQ-UHFFFAOYSA-N 4-methyl-3-oxopent-4-ene-1-sulfonic acid Chemical compound CC(=C)C(=O)CCS(O)(=O)=O SVYPQURSUBDSIQ-UHFFFAOYSA-N 0.000 description 1
- RNIHAPSVIGPAFF-UHFFFAOYSA-N Acrylamide-acrylic acid resin Chemical compound NC(=O)C=C.OC(=O)C=C RNIHAPSVIGPAFF-UHFFFAOYSA-N 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- PQUCIEFHOVEZAU-UHFFFAOYSA-N Diammonium sulfite Chemical compound [NH4+].[NH4+].[O-]S([O-])=O PQUCIEFHOVEZAU-UHFFFAOYSA-N 0.000 description 1
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- HVUMOYIDDBPOLL-XWVZOOPGSA-N Sorbitan monostearate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O HVUMOYIDDBPOLL-XWVZOOPGSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical class OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- 229920006322 acrylamide copolymer Polymers 0.000 description 1
- 125000000751 azo group Chemical group [*]N=N[*] 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 239000012986 chain transfer agent Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 125000004386 diacrylate group Chemical group 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000010528 free radical solution polymerization reaction Methods 0.000 description 1
- 238000010413 gardening Methods 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- FQPSGWSUVKBHSU-UHFFFAOYSA-N methacrylamide Chemical compound CC(=C)C(N)=O FQPSGWSUVKBHSU-UHFFFAOYSA-N 0.000 description 1
- 125000005395 methacrylic acid group Chemical group 0.000 description 1
- GBMDVOWEEQVZKZ-UHFFFAOYSA-N methanol;hydrate Chemical compound O.OC GBMDVOWEEQVZKZ-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- QRWZCJXEAOZAAW-UHFFFAOYSA-N n,n,2-trimethylprop-2-enamide Chemical compound CN(C)C(=O)C(C)=C QRWZCJXEAOZAAW-UHFFFAOYSA-N 0.000 description 1
- 229940088644 n,n-dimethylacrylamide Drugs 0.000 description 1
- YLGYACDQVQQZSW-UHFFFAOYSA-N n,n-dimethylprop-2-enamide Chemical compound CN(C)C(=O)C=C YLGYACDQVQQZSW-UHFFFAOYSA-N 0.000 description 1
- 229920005615 natural polymer Polymers 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 229920002401 polyacrylamide Polymers 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920000768 polyamine Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 229920005862 polyol Polymers 0.000 description 1
- 150000003077 polyols Chemical class 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000001587 sorbitan monostearate Substances 0.000 description 1
- 235000011076 sorbitan monostearate Nutrition 0.000 description 1
- 229940035048 sorbitan monostearate Drugs 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 239000007785 strong electrolyte Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000010557 suspension polymerization reaction Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Landscapes
- Absorbent Articles And Supports Therefor (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
本発明は新規な吸水性樹脂の製造法に関する。
更に詳しくは、特定の構成単量体の所定量を重合
させて得られ、殊に電解質水溶液の吸収能に優れ
た吸水性樹脂の製造法に関する。
吸水性樹脂は近年、生理用品、衛生用品、保水
剤、汚泥凝固剤、、増粘剤、結露防止剤、さらに
各種薬品のリリースコントロール剤などの種々の
用途に利用されている。
これら吸水性樹脂としては、澱粉−アクリロニ
リルグラフト重合体の加水分解物、カルボキシメ
チルセルローズ、ポリアクリル酸塩架橋物、その
他ポリビニルアルコール系、ポリエチレンオキサ
イド系、ポリアクリロニトリル系などが知られて
いる。かかる吸水性樹脂のうち、澱粉−アクリロ
ニトリルグラフト重合体の加水分解物は、比較的
高い吸水能を有するが、天然高分子である澱粉を
使用しているため耐熱性、腐敗分解等に欠点があ
り、その製造方法も煩雑である。カルボキシメチ
ルセルロース、ポリエチレンオキサイド系及びポ
リアクリロニトリル系では未だ満足すべき吸水能
を有するものは得られていない。従来公知の吸水
性樹脂の中で、吸水能及び品質安定性ともに優れ
た樹脂として、ポリアクリル酸塩架橋物が有望視
されている。しかしながら該樹脂といえども電解
質水溶液の吸収能に関しては未だ満足しうるもの
ではない。しかして上記電解質水溶液の吸収能と
は、吸水性樹脂の用途に応じて強く要求されるも
のであり、例えば紙おむつ用では***尿が電解質
水溶液であり、その吸収能が良好であることが要
望される。また土壌改良用でも土中には通常溶存
イオンが存在しており、単なる吸水能のみなら
ず、かかる溶存イオンを含む電解質水溶液の吸収
能が強く切望される。近時、ポリアクリル酸系吸
水性樹脂例えばアクリル酸−スルホン基含有単量
体を逆相懸濁重合して得られる自己架橋型吸水性
樹脂が上記電解質水溶液の吸収能を有する吸水樹
脂として提案されているが、該樹脂の電解質水溶
液吸収能は尚不充分であり、改良の余地がある。
本発明者らは、上記の通り斯界で切望されてい
る優れた電解質水溶液吸収能を有する吸水樹脂を
提供することを目的として鋭意研究を重ねた結
果、下記特定の４種の単量体を夫々所定割合で重
合反応させて得られる新しい樹脂が、上記目的に
合致する優れた電解質水溶液吸収能を具備すると
いう事実を発見し、ここに本発明を完成するに至
つた。
即ち本発明は(a)一般式
〔式中R1は水素原子又はメチル基を示す〕
で表わされる化合物、
(b) 一般式
〔式中R2は水素原子又はメチル基を示し、M1は
水素原子、アルカリ金属原子又はアンモニウム基
を示す〕
で表わされる化合物、
(c) 一般式
〔式中R3は水素原子又はメチル基、M2は水素
原子、アルカリ金属原子又はアンモニウム基、Ｘ
は酸素原子又はイミノ基及びＹは炭素数２〜10の
直鎖状もしくは分岐鎖状アルキレン基を示す〕
で表わされる化合物、及び(d)水混和性乃至水溶性
ジビニル系化合物を構成単量体とする樹脂であつ
て、上記(a)成分、(b)成分及び(c)成分の割合が30〜
80、５〜55及び５〜25モル％であり、且つ(d)成分
の割合が上記(a)成分、(b)成分及び(c)成分の合計重
量に対して0.001〜0.1重量％であることを特徴と
する吸水性樹脂の製造法に係る。
本発明方法により得られる吸水性樹脂は、上記
特定の単量体を構成成分とすることに基づいて、
優れた吸水能を有すると共に、従来公知のこの種
吸水性樹脂には見られない良好な電解質水溶液吸
収能を具備している。従つてこれは公知の吸水性
樹脂と同様の用途に一層有利に利用できると共
に、従来の吸水性樹脂では、効果の見られなかつ
た電解質水溶液の吸収能を要求される用途にも有
効に利用できる。
本発明吸水性樹脂製造物は、上記の通り特定の
４種の単量体をその構成成分とすることを必須の
要件とする。該単量体中(a)成分は、上記一般式
〔〕で表わされるものであり、その具体例とし
ては例えばアクリルアミド、メタアクリルアミ
ド、Ｎ，Ｎ−ジメチルアクリルアミド、Ｎ，Ｎ−
ジメチルメタクリルアミドを例示することができ
る。
単量体成分(b)は、前記一般式〔〕で表わさ
れ、該成分の具体例としては、アクリル酸、メタ
クリル酸、これらの塩、例えば水酸化カリウム、
水酸化ナトリウムなどのアルカリ金属の塩、アン
モニウム塩等が挙げられる。
単量体成分(c)は、前記一般式〔〕で表わさ
れ、該成分の具体例としては、例えば２−アクリ
ルアミド−２−メチルプロパンスルホン酸、２−
メタクリルアミド−２−メチルプロパンスルホン
酸、２−アクリロイルエタンスルホン酸、２−ア
クリロイルプロパンスルホン酸、２−メタクロイ
ルエタンスルホン酸、２−メタクリロイルプロパ
ンスルホン酸、２−アクリロイルオキシエタンス
ルホン酸、２−アクリロイルオキシプロパンスル
ホン酸、２−メタクリロイルオキシエタンスルホ
ン酸、２−メタクリロイルオキシプロパンスルホ
ン酸等並びにこれらのアルカリ金属塩及びアンモ
ニウム塩を挙げることができる。
単量体成分(d)は、水混和性乃至水溶性ジビニル
系化合物であつて、この成分は前記単量体成分(a)
〜(d)及び水からなる混合単量体水溶液中に均一に
溶解される各種のジビニル系化合物を包含する。
かかるジビニル系化合物としては、例えばＮ，Ｎ
−メチレンビスアクリルアミド、Ｎ，Ｎ−メチレ
ンビスメタクリルアミドなどのビスアクリルアミ
ド類；下記一般式〔〕で表わされるジアクリル
（又はメタクリル）酸エステル類；下記一般式
〔〕で表わされるジアクリルアミド類等の通常
の架橋剤を例示できる。これらのうちで特にＮ，
Ｎ−メチレンビスアクリルアミド、Ｎ，Ｎ−メチ
レンビスメタクリルアミド等のビスアクリルアミ
ド類は好適である。
〔式中Ｘはエチレン、プロピレン、２−ヒドロ
キシプロピレン、（−CH2CH2O）−oCH2CH2−又は
The present invention relates to a novel method for producing a water absorbent resin.
More specifically, the present invention relates to a method for producing a water-absorbing resin that is obtained by polymerizing a predetermined amount of a specific constituent monomer and has particularly excellent absorption ability for an aqueous electrolyte solution. In recent years, water-absorbing resins have been used for a variety of purposes, including sanitary products, sanitary products, water retention agents, sludge coagulants, thickeners, anti-condensation agents, and release control agents for various chemicals. As these water-absorbing resins, hydrolysates of starch-acrylonyl graft polymers, carboxymethyl cellulose, polyacrylate cross-linked products, and other polyvinyl alcohol-based, polyethylene oxide-based, and polyacrylonitrile-based resins are known. Among such water-absorbing resins, hydrolysates of starch-acrylonitrile graft polymers have a relatively high water-absorbing capacity, but because they use starch, which is a natural polymer, they have drawbacks such as heat resistance and rot decomposition. , the manufacturing method is also complicated. Among carboxymethyl cellulose, polyethylene oxide, and polyacrylonitrile, none with satisfactory water absorption ability has yet been obtained. Among conventionally known water-absorbing resins, cross-linked polyacrylates are considered promising as resins with excellent water-absorbing ability and quality stability. However, even with this resin, the ability to absorb an aqueous electrolyte solution is still not satisfactory. However, the absorption capacity of the electrolyte aqueous solution is strongly required depending on the use of the water-absorbing resin. For example, in the case of disposable diapers, excreted urine is an electrolyte aqueous solution, and a good absorption capacity is required. Ru. Furthermore, even for soil improvement, dissolved ions are usually present in the soil, and it is strongly desired to have not only a mere water absorption ability but also an ability to absorb an electrolyte aqueous solution containing such dissolved ions. Recently, self-crosslinking water-absorbing resins obtained by reverse-phase suspension polymerization of polyacrylic acid-based water-absorbing resins, such as acrylic acid-sulfone group-containing monomers, have been proposed as water-absorbing resins that have the ability to absorb the electrolyte aqueous solution. However, the ability of this resin to absorb an aqueous electrolyte solution is still insufficient, and there is room for improvement. As a result of intensive research aimed at providing a water-absorbing resin with excellent electrolyte aqueous solution absorption ability, which is highly desired in the industry as described above, the present inventors have developed the following four specific monomers. The present invention was completed based on the discovery that a new resin obtained by a polymerization reaction at a predetermined ratio has an excellent ability to absorb an aqueous electrolyte solution that meets the above objectives. That is, the present invention relates to (a) general formula [In the formula, R 1 represents a hydrogen atom or a methyl group] A compound represented by (b) general formula [In the formula, R 2 represents a hydrogen atom or a methyl group, and M 1 represents a hydrogen atom, an alkali metal atom or an ammonium group] A compound represented by (c) general formula [In the formula, R 3 is a hydrogen atom or a methyl group, M 2 is a hydrogen atom, an alkali metal atom or an ammonium group,
represents an oxygen atom or an imino group, and Y represents a linear or branched alkylene group having 2 to 10 carbon atoms] and monomers constituting the water-miscible or water-soluble divinyl compound (d) A resin in which the ratio of the above components (a), (b) and (c) is 30 to 30.
80, 5 to 55 and 5 to 25 mol%, and the proportion of component (d) is 0.001 to 0.1% by weight based on the total weight of components (a), (b) and (c). The present invention relates to a method for producing a water-absorbing resin characterized by the following. The water-absorbing resin obtained by the method of the present invention is based on the above-mentioned specific monomer as a constituent component.
It has an excellent water absorbing ability and also has a good electrolyte aqueous solution absorbing ability not found in conventionally known water absorbing resins of this type. Therefore, it can be used more advantageously in the same applications as known water-absorbing resins, and can also be effectively used in applications that require the ability to absorb electrolyte aqueous solutions, which conventional water-absorbing resins have no effect on. . As mentioned above, the water-absorbing resin product of the present invention is required to contain four specific types of monomers as its constituent components. Component (a) in the monomer is represented by the above general formula [], and specific examples thereof include acrylamide, methacrylamide, N,N-dimethylacrylamide, N,N-
Dimethylmethacrylamide can be exemplified. The monomer component (b) is represented by the general formula [], and specific examples of the component include acrylic acid, methacrylic acid, salts thereof, such as potassium hydroxide,
Examples include alkali metal salts such as sodium hydroxide, ammonium salts, and the like. The monomer component (c) is represented by the general formula [], and specific examples of the component include 2-acrylamido-2-methylpropanesulfonic acid, 2-
Methacrylamido-2-methylpropanesulfonic acid, 2-acryloylethanesulfonic acid, 2-acryloylpropanesulfonic acid, 2-methacryloylethanesulfonic acid, 2-methacryloylpropanesulfonic acid, 2-acryloyloxyethanesulfonic acid, 2-acryloyl Examples include oxypropanesulfonic acid, 2-methacryloyloxyethanesulfonic acid, 2-methacryloyloxypropanesulfonic acid, and their alkali metal salts and ammonium salts. Monomer component (d) is a water-miscible or water-soluble divinyl compound, and this component is the same as monomer component (a).
It includes various divinyl compounds that are uniformly dissolved in a mixed monomer aqueous solution consisting of (d) and water.
Such divinyl compounds include, for example, N,N
- Bisacrylamides such as methylenebisacrylamide and N,N-methylenebismethacrylamide; diacrylic (or methacrylic) acid esters represented by the following general formula []; ordinary diacrylamides such as the following general formula [] Examples include crosslinking agents. Among these, especially N,
Bisacrylamides such as N-methylenebisacrylamide and N,N-methylenebismethacrylamide are preferred. [In the formula, X is ethylene, propylene, 2-hydroxypropylene, (-CH 2 CH 2 O)- o CH 2 CH 2 - or
【式】基を示し、ｎ
及びｍは５〜40の整数を示す。）
該一般式〔〕で表わされる化合物は、例えば
エチレングリコール、プロピレングリコール、グ
リセリン、ポリエチレングリコール、ポリプロピ
レングリコールなどのポリオール類とアクリル酸
又はメタクリル酸とを常法に従い反応させること
により得られる。
〔式中ｌは２又は３を示す。〕
該一般式〔〕で表わされる化合物は、例えば
ジエチレントリアミン、トリエチレンテトラミン
などのアリアルキルンポリアミン類とアクリル酸
とを常法に従い反応させることにより得られる。
上記単量体成分(a)〜(d)の使用量は、得られる樹
脂の吸水能及び電解質水溶液吸収能を考慮して通
常構成単量体の組成が、モル換算で(a)／(b)／(c)＝
30〜80／５〜55／５〜25（モル％）の範囲であり、
且つ(d)成分が(a)，(b)及び(c)成分の合計重量に対し
て0.001〜0.1重量％、より好ましくは(a)／(b)／(c)
＝40〜70／10〜50／10〜20（モル％）、(d)成分が
0.005〜0.05重量％とするのがよい。本発明の吸
水性樹脂の特徴である電解質水溶液吸収能とは、
食塩水、塩化カルシウム水溶液、人工尿などの電
解質水溶液の吸収能を意味する。該吸収能の改良
には、特に非電解質たる水溶性単量体、即ち前記
成分(a)及び強電解質たる水溶性単量体、即ち前記
成分(c)の併用が必須であり、しかも之等各成分が
前記使用範囲内にあることが必要である。前記成
分(a)及び(c)の使用量が前記範囲に満たない場合
は、高吸水能の吸水性樹脂を得ることができたと
しても、電解質水溶液の吸収能は劣るため好まし
くない。逆に成分(a)の使用量が前記範囲を超える
場合は、吸水能が低下する傾向にあり、また成分
(c)が前記範囲を超える場合は重合速度が低下する
傾向にあり、得られる重合体中の残存単量体量が
増加しそのため吸水能、電解質水溶液吸収能とも
に低下する傾向を生じ好ましくない。また成分(b)
は、(a)〜(d)成分のうちで、特に吸水能に強い影響
を及ぼすため、前記範囲を満足する必要がある。
尚該成分(b)は通常遊離のカルボン酸として使用す
るよりむしろ部分ないし完全中和して使用される
方が好ましく、本発明においては該(b)成分の中和
度を約75〜100％の範囲とするのがよい。架橋剤
たる成分(d)の使用量は、吸水能、ゲル強度に影響
を及ぼし、該使用量があまり多すぎる場合は、得
られる重合体はその吸水時のゲル強度が過大とな
り吸水性が低下する。また少なすぎる場合は、逆
にゲル強度の小さいゾル状の重合体が得られ、こ
れも吸水性が低く、いずれも好ましくない。
本発明の吸水性樹脂は、上記成分(a)乃至成分(d)
の夫々所定量を利用して、通常の水溶性単量体例
えばアクリル酸、アクリル酸塩等の重合方法と同
様にして、水溶液重合、逆相乳化重合、逆相懸濁
重合等の各種方法により収得できる。特に好まし
い重合方法は水溶液重合方法であり、その際、原
料単量体成分(a)〜(d)の水溶液の全単量体濃度を60
〜85重量％、好ましくは70〜80重量％とした加温
水溶液を調製し、該水溶液に通常の重合反応開始
剤を添加して重合反応を行なうのが好適である。
この方法によれば、極めて短時間内に充分に重合
反応が進行し、しかもこの重合反応の反応熱によ
つて、反応系内より水分が迅速に気化し、これに
よつて引き続き何らの乾燥工程を要することなく
直接に所望の低含水率でしかも優れた吸水性及び
電解質水溶液吸収能を有する吸水性樹脂乾燥固体
を収得できる。これは容易に粉砕することがで
き、これによつて所望の用途に好適な粉末とする
ことができる。しかも上記方法によれば、外部加
熱及び乾燥工程の採用によるオーバーヒート等に
起因する架橋度の不均一化やこれによる吸水能、
電解質水溶液吸収能の低下等のおそれもなく非常
に良好な品質を具備する所望の吸水性の樹脂固体
を常に安定して収得できる。更に上記方法に従え
ば、重合反応及び水分の気化が外部加熱なしに非
常に迅速に、通常数分以内に完結するものであ
り、作業効率が極めて良好であり、熱エネルギー
の消費も非常に少ない利点があり、更に重合反応
率も高く、工業的実施に好適なものである。
上記好ましい重合方法は、より詳細には、まず
上記単量体成分(a)〜(d)を所定割合で含有し、且つ
混合単量体濃度が60〜85重量％の範囲の混合単量
体の加温水溶液を調製し、これにより得られる水
溶液を予め加温後、これに重合反応開始剤を添加
して重合反応（及び架橋反応）を開始させること
により行なわれる。ここで加温条件は、重合反応
開始剤の添加により重合反応が開始されることを
前提として特に制限はないが、通常約55〜80℃、
好ましくは60〜75℃程度とすればよい。また重合
反応開始剤としては、従来よりポリアクリル酸
塩、ポリアクリルアミド等の製造に供されている
各種のものをいずれも使用できる。その具体例と
しては例えばアルカリ金属の亜硫酸塩もしくは重
亜硫酸塩、亜硫酸アンモニウム、重亜硫酸アンモ
ニウム等の還元剤と、アルカリ金属の過硫酸塩、
過硫酸アンモニウム等の開始剤との組み合せより
なるレドツクス系開始剤やアゾビスイソブチロニ
トリル、４−ｔ−ブチルアゾ−4′−シアノ吉草
酸、４，4′−アゾビス（４−シアノ吉草酸）、２，
2′−アゾビス（２−アミジノプロパン）塩酸塩等
の所謂アゾ系開始剤等あるいはこれらの二種以上
の組合せを適宜選択使用できる。これらの内で
は、特に過硫酸アンモニウムと亜硫酸水素ナトリ
ウムとの組合せよりなるレドツクス系開始剤及び
アゾビスイソブチロニトリル又は２，2′−アゾビ
ス（２−アミジノプロパン）塩酸塩等のアゾ系開
始剤等が好適である。上記重合開始剤は、通常水
溶液の形態で有利に用いられるが、例えば適当な
溶媒で希釈して用いることもできる。かかる重合
開始剤の使用量は、通常のそれと特に異ならず、
通常固型分重量で前記混合単量体の合計重量に対
して0.1〜10％、より好ましくは0.5〜５％程度と
するのがよい。また上記重合反応開始剤の種類及
び使用量によつては、これと共にイソプロピルア
ルコールやアルキルメルカプタン等の通常の連鎖
移動剤を併用して、生成する重合体の分子量を調
節することができる。
上記混合単量体加温水溶液に重合反応開始剤を
添加することにより、外部加熱を何ら行なわずと
も重合反応及び水分の気化が起る。上記重合反応
開始剤の添加による重合反応及び水分の気化は、
より有利には混合単量体加温水溶液に重合反応開
始剤又はその水溶液の所定量を添加混合し、この
混合液を移動するベルト上に流下延展させること
により実施される。重合反応開始剤を水溶液の形
態で用いる場合、得られる混合液中の総単量体濃
度が前述した60〜85重量％の範囲を下回らないよ
うにしなければならない。また上記ベルト上への
混合液の流下に当つては、該ベルトの混合液流下
部分に更に重合反応開始剤を配置しておくことも
できる。
上記混合単量体加温水溶液への重合反応開始剤
の添加混合によれば、混合後極めて速やかに重合
反応が開始され、短時間に、通常30秒から10分程
度で反応は完結する。しかもこの反応は発熱反応
であり、反応系はこの重合熱により速やかに約
100〜130℃程度に上昇し、これによつて系内の水
分は、外部より他に何ら加熱等を行なわずとも急
速に気化蒸発し、所望の低含水率の重合体（乾燥
固体）が収得される。得られる重合体の含水率は
反応条件等により若干異なるが通常約15％以下、
より好ましくは約12％以下であり、これは引き続
き何らの乾燥工程を要することなく、単に常法に
従い粉砕等を行なうのみで所望の粉末製品とする
ことができる。
かくして上記方法によれば、極めて迅速且つ容
易に通常含水率が15％以下の乾燥固体状態の本発
明による吸水性樹脂（アクリル酸−アクリルアミ
ド系共重合体の架橋物）を収得できる。該重合体
中に残存する単量体は、重合体に対し僅か
2000ppm以下であり、重合率も極めて良好であ
る。
かくして得られる本発明による樹脂乾燥固体
は、これを引き続き通常の粉砕機等を用いて容易
に粉末化することができ、得られる粉末は優れた
吸水能並びに優れた電解質水溶液吸収能を有し、
例えば生理用品、紙おむつ、使い捨てぞうきん等
の衛生用品や農園芸関係の保水剤、諸工業用脱水
剤、汚泥凝固剤、増粘剤、建材の結露防止剤、更
に各種薬材のリリースコントロール剤等の各種用
途に利用できる。
以下本発明を更に詳しく説明するため本発明に
よる樹脂及び比較のための樹脂の製造例を実施例
及び比較例として挙げる。
実施例 １
アクリルアミド（以下AMと略す）35.5ｇ、純
度98％のアクリル酸（以下AAと略す）22.1ｇ、
２−アクリロイルアミノ−２−メチルプロパンス
ルホン酸（以下AMPSと略す）41.4ｇ及び水18.8
ｇを加え、50℃まで加温し溶解させる。次いで中
和剤として純度96％の水酸化カリウム29.2ｇ（ア
クリル酸の中和度が100％となる量）を、前記単
量体水溶液中へ、冷却しつつ徐々に添加し中和を
行なう。更にＮ，Ｎ−メチレンビスアクリルアミ
ド（以下MBAMと略す）0.014ｇを添加して、単
量体濃度80重量％の混合単量体水溶液を調製す
る。
該水溶液を60℃に保温し、これに２，2′−アゾ
ビス（２−アミジノプロパン）塩酸塩の10％水溶
液11.8ｇを添加し、該混合液をエンドレスの移動
ベルト上に厚さ10mmに層状流下延長させる。約１
分後に反応が開始され反応は約30秒で完結する。
このようにして得られた帯状乾燥固体は粉砕機に
より粉砕することによつて粉末化される。得られ
る本発明による吸水性樹脂粉末の吸水能は脱イオ
ン水の場合900倍であり、0.9％塩化ナトリウム水
溶液の場合90倍及び0.5％塩化カルシウム水溶液
の場合50倍であつた。また含水率は８％であつ
た。
実施例 ２〜９
実施例１においてAM、AA、AMPS及び
MBAMの使用量、混合単量体濃度及び保温温度
のいずれか少なくとも一種を第１表に示す通りに
変化させたほかは、同様にして重合反応を行ない
重合体を得る。得られた重合体のの含水率及び各
吸収能を第１表に示す。
比較例 １〜４
実施例１において、AMまたはAAを使用せず
その他の単量体の使用量を第２表に示す通りに変
化させたほかは、同様にして重合反応を行ない重
合体を得る。得られた重合体の含水率及び各吸収
能を第１表に示す。
比較例 ５〜７
市販デンプン系吸収性樹脂（比較例５）、市販
アクリル酸系吸水性樹脂（）（比較例６）及び
市販アクリル酸系吸水性樹脂（）（比較例７）
の各吸収能を測定した。結果を下記第１表に示
す。[Formula] represents a group, and n and m represent integers of 5 to 40. ) The compound represented by the general formula [] can be obtained by reacting polyols such as ethylene glycol, propylene glycol, glycerin, polyethylene glycol, and polypropylene glycol with acrylic acid or methacrylic acid according to a conventional method. [In the formula, l represents 2 or 3. ] The compound represented by the general formula [ ] can be obtained by reacting an arylkyl polyamine such as diethylenetriamine or triethylenetetramine with acrylic acid according to a conventional method. The amount of the above monomer components (a) to (d) to be used is determined by considering the water absorption capacity and electrolyte aqueous solution absorption capacity of the resulting resin, and usually the composition of the constituent monomers is (a) / (b) on a molar basis. )／(c)=
The range is 30-80/5-55/5-25 (mol%),
and component (d) is 0.001 to 0.1% by weight based on the total weight of components (a), (b) and (c), more preferably (a)/(b)/(c)
=40~70/10~50/10~20 (mol%), component (d)
The content is preferably 0.005 to 0.05% by weight. The electrolyte aqueous solution absorption ability, which is a feature of the water absorbent resin of the present invention, is as follows:
It refers to the ability to absorb electrolyte aqueous solutions such as saline, calcium chloride aqueous solutions, and artificial urine. In order to improve the absorption capacity, it is essential to use a water-soluble monomer as a non-electrolyte, i.e., component (a), and a water-soluble monomer as a strong electrolyte, i.e., component (c), in combination. It is necessary that each component be within the above usage range. If the amount of the components (a) and (c) used is less than the above range, even if a water absorbent resin with high water absorption capacity can be obtained, the absorption capacity of the electrolyte aqueous solution will be poor, which is not preferable. Conversely, if the amount of component (a) used exceeds the above range, the water absorption capacity tends to decrease, and the amount of component (a) used exceeds the above range.
If (c) exceeds the above range, the polymerization rate tends to decrease, and the amount of residual monomer in the resulting polymer increases, which tends to lower both the water absorption capacity and the electrolyte aqueous solution absorption capacity, which is undesirable. Also component (b)
Among the components (a) to (d), these have a particularly strong influence on the water absorption capacity, so it is necessary to satisfy the above range.
Note that component (b) is usually preferably used as a partially or completely neutralized rather than as a free carboxylic acid, and in the present invention, the degree of neutralization of component (b) is approximately 75 to 100%. It is recommended that the range be within the range of . The amount of component (d), which is a crosslinking agent, affects water absorption capacity and gel strength; if the amount used is too large, the resulting polymer will have excessive gel strength upon water absorption, resulting in decreased water absorption. do. On the other hand, if the amount is too small, a sol-like polymer with low gel strength will be obtained, which will also have low water absorption, which is not preferable. The water absorbent resin of the present invention comprises the above components (a) to (d).
Using prescribed amounts of each of You can earn it. A particularly preferred polymerization method is an aqueous solution polymerization method, in which the total monomer concentration of the aqueous solution of raw material monomer components (a) to (d) is reduced to 60%.
It is preferable to prepare a heated aqueous solution having a concentration of 85% to 85% by weight, preferably 70 to 80% by weight, and to carry out the polymerization reaction by adding a conventional polymerization reaction initiator to the aqueous solution.
According to this method, the polymerization reaction progresses sufficiently within an extremely short period of time, and the reaction heat of this polymerization reaction quickly evaporates water from the reaction system, thereby preventing any subsequent drying process. It is possible to directly obtain a dry solid water-absorbing resin having a desired low water content and excellent water absorbency and ability to absorb an aqueous electrolyte solution without the need for water absorption. It can be easily ground into a powder suitable for the desired application. Moreover, according to the above method, the degree of crosslinking becomes uneven due to overheating due to the external heating and drying process, and the water absorption capacity due to this becomes uneven.
A desired water-absorbing resin solid having very good quality can always be stably obtained without fear of a decrease in the electrolyte aqueous solution absorption capacity. Furthermore, if the above method is followed, the polymerization reaction and moisture vaporization are completed very quickly, usually within a few minutes, without external heating, resulting in extremely high working efficiency and very low thermal energy consumption. It has advantages and also has a high polymerization reaction rate, making it suitable for industrial implementation. In more detail, the above preferred polymerization method first involves forming a mixed monomer containing the above monomer components (a) to (d) in a predetermined ratio and having a mixed monomer concentration in the range of 60 to 85% by weight. This is carried out by preparing a heated aqueous solution of , warming the resulting aqueous solution in advance, and then adding a polymerization reaction initiator thereto to start the polymerization reaction (and crosslinking reaction). The heating conditions here are not particularly limited on the premise that the polymerization reaction is initiated by the addition of a polymerization initiator, but are usually about 55 to 80°C;
Preferably, the temperature may be about 60 to 75°C. Furthermore, as the polymerization reaction initiator, any of the various initiators that have been conventionally used in the production of polyacrylates, polyacrylamides, etc. can be used. Specific examples include reducing agents such as alkali metal sulfites or bisulfites, ammonium sulfite, ammonium bisulfite, and alkali metal persulfates,
Redox initiators in combination with initiators such as ammonium persulfate, azobisisobutyronitrile, 4-t-butylazo-4'-cyanovaleric acid, 4,4'-azobis(4-cyanovaleric acid), 2,
So-called azo initiators such as 2'-azobis(2-amidinopropane) hydrochloride, etc., or a combination of two or more of these can be appropriately selected and used. Among these, redox initiators consisting of a combination of ammonium persulfate and sodium bisulfite, and azo initiators such as azobisisobutyronitrile or 2,2'-azobis(2-amidinopropane) hydrochloride, etc. is suitable. The above polymerization initiator is usually advantageously used in the form of an aqueous solution, but it can also be used after being diluted with an appropriate solvent, for example. The amount of such polymerization initiator used is not particularly different from that of usual,
Usually, the solid content is preferably about 0.1 to 10%, more preferably about 0.5 to 5%, based on the total weight of the mixed monomers. Further, depending on the type and amount of the polymerization reaction initiator used, a common chain transfer agent such as isopropyl alcohol or alkyl mercaptan may be used together with the polymerization reaction initiator to control the molecular weight of the resulting polymer. By adding a polymerization initiator to the heated aqueous solution of mixed monomers, the polymerization reaction and vaporization of water occur without any external heating. The polymerization reaction and vaporization of water due to the addition of the polymerization initiator are as follows:
More preferably, it is carried out by adding and mixing a predetermined amount of a polymerization reaction initiator or its aqueous solution to a heated aqueous solution of mixed monomers, and flowing and spreading this mixed solution onto a moving belt. When the polymerization reaction initiator is used in the form of an aqueous solution, the total monomer concentration in the resulting mixed solution must not fall below the above-mentioned range of 60 to 85% by weight. Further, when the mixed liquid flows down onto the belt, a polymerization reaction initiator may be further placed in the part of the belt where the mixed liquid flows down. By adding and mixing the polymerization reaction initiator to the heated aqueous solution of mixed monomers, the polymerization reaction starts very quickly after mixing, and the reaction is completed in a short time, usually about 30 seconds to 10 minutes. Moreover, this reaction is an exothermic reaction, and the reaction system quickly changes to approximately
The temperature rises to approximately 100 to 130℃, and as a result, the moisture in the system is rapidly vaporized without any external heating, and the desired low moisture content polymer (dry solid) is obtained. be done. The water content of the resulting polymer varies slightly depending on the reaction conditions, etc., but is usually about 15% or less.
More preferably, it is about 12% or less, and the desired powder product can be obtained by simply pulverizing or the like according to a conventional method without requiring any subsequent drying step. Thus, according to the above method, the water-absorbing resin (crosslinked product of acrylic acid-acrylamide copolymer) according to the present invention in a dry solid state with a water content of usually 15% or less can be obtained very quickly and easily. The monomer remaining in the polymer is very small compared to the polymer.
It is 2000 ppm or less, and the polymerization rate is also extremely good. The resin dry solid according to the present invention thus obtained can be easily pulverized using a conventional pulverizer or the like, and the resulting powder has excellent water absorption ability and excellent electrolyte aqueous solution absorption ability,
For example, sanitary products such as sanitary products, disposable diapers, disposable cloths, water retention agents for agriculture and gardening, dehydration agents for various industries, sludge coagulants, thickeners, anti-condensation agents for building materials, and release control agents for various pharmaceuticals. Can be used for various purposes. In order to explain the present invention in more detail, production examples of resins according to the present invention and resins for comparison will be given below as Examples and Comparative Examples. Example 1 35.5 g of acrylamide (hereinafter abbreviated as AM), 22.1 g of acrylic acid with a purity of 98% (hereinafter abbreviated as AA),
41.4g of 2-acryloylamino-2-methylpropanesulfonic acid (hereinafter abbreviated as AMPS) and 18.8g of water
Add g and warm to 50℃ to dissolve. Next, 29.2 g of potassium hydroxide with a purity of 96% (the amount that makes the degree of neutralization of acrylic acid 100%) as a neutralizing agent is gradually added to the aqueous monomer solution while cooling to effect neutralization. Furthermore, 0.014 g of N,N-methylenebisacrylamide (hereinafter abbreviated as MBAM) is added to prepare a mixed monomer aqueous solution with a monomer concentration of 80% by weight. The aqueous solution was kept at 60°C, 11.8 g of a 10% aqueous solution of 2,2'-azobis(2-amidinopropane) hydrochloride was added, and the mixed solution was layered on an endless moving belt to a thickness of 10 mm. Extend the flow. Approximately 1
The reaction starts after a few minutes and is completed in about 30 seconds.
The strip-shaped dry solid thus obtained is pulverized by pulverizing it with a pulverizer. The water absorption capacity of the resulting water-absorbent resin powder according to the present invention was 900 times higher in the case of deionized water, 90 times higher in the case of 0.9% aqueous sodium chloride solution, and 50 times higher in the case of 0.5% aqueous calcium chloride solution. Moreover, the moisture content was 8%. Examples 2 to 9 In Example 1, AM, AA, AMPS and
A polymer was obtained by carrying out the polymerization reaction in the same manner, except that at least one of the amount of MBAM used, the mixed monomer concentration, and the insulating temperature was changed as shown in Table 1. Table 1 shows the water content and absorption capacity of the obtained polymers. Comparative Examples 1 to 4 A polymer was obtained by performing a polymerization reaction in the same manner as in Example 1, except that AM or AA was not used and the amounts of other monomers were changed as shown in Table 2. . Table 1 shows the water content and absorption capacity of the obtained polymers. Comparative Examples 5 to 7 Commercially available starch-based absorbent resin (Comparative example 5), commercially available acrylic acid-based water absorbent resin () (Comparative example 6), and commercially available acrylic acid-based water absorbent resin () (Comparative example 7)
Each absorption capacity was measured. The results are shown in Table 1 below.
【表】
実施例 10
撹拌機、還流冷却器、温度計、窒素ガス導入管
を備えた２容フラスコにAM35.5ｇ、AA22.1
ｇ、AMPS41.4ｇ及び水626ｇを加え溶解させ冷
却しながら48％水酸化カリウム58.4ｇを添加した
後、MBAM0.021ｇを加え濃度15％の混合単量体
水溶液を調整する。該水溶液に充分に窒素ガスを
吹き込んだ後、25℃にて過硫酸アンモニウムの１
％水溶液６ｇと亜硫酸水素ナトリウムの１％水溶
液６ｇを加え撹拌下に70℃で３時間重合反応を行
ない重合体を得る。該重合体を水−メタノール混
合溶液で洗浄し、105℃で８時間乾燥した後、粉
砕して本発明による吸水性樹脂粉末を得る。
得られた樹脂粉末の各吸収能を第２表に示す。
実施例 11
AM35.5ｇ、AA22.1ｇ、AMPS41.4ｇ及び水
136.4ｇを加え、更に冷却しながら48％水酸化カ
リウム58.4ｇを添加した後、MBAM0.021ｇと過
硫酸カリウム0.32ｇを溶解させ、濃度40％の混合
単量体水溶液を調製する。２容フラスコにシク
ロヘキサン556ｇとソルビタンモノステアレート
4.7ｇを溶解させ充分窒素置換した後、撹拌下に
前記混合単量体水溶液を滴下し懸濁させる。更に
60℃で３時間重合反応を行ない重合体懸濁物を得
る。これを減圧下で蒸発乾固することにより微粒
状の本発明による吸水性樹脂粉末を得る。
得られた樹脂粉末の各吸収能を第２表に示す。[Table] Example 10 Add 35.5 g of AM and 22.1 g of AA to a 2-volume flask equipped with a stirrer, reflux condenser, thermometer, and nitrogen gas inlet tube.
g, 41.4 g of AMPS and 626 g of water were added, dissolved, and while cooling, 58.4 g of 48% potassium hydroxide was added, and then 0.021 g of MBAM was added to prepare a mixed monomer aqueous solution with a concentration of 15%. After sufficiently blowing nitrogen gas into the aqueous solution, 1% ammonium persulfate was added at 25°C.
% aqueous solution and 6 g of a 1% aqueous solution of sodium bisulfite were added, and a polymerization reaction was carried out at 70° C. for 3 hours with stirring to obtain a polymer. The polymer is washed with a water-methanol mixed solution, dried at 105° C. for 8 hours, and then pulverized to obtain a water-absorbing resin powder according to the present invention. Table 2 shows the absorption capacity of each of the obtained resin powders. Example 11 AM35.5g, AA22.1g, AMPS41.4g and water
After adding 136.4 g and further adding 58.4 g of 48% potassium hydroxide while cooling, 0.021 g of MBAM and 0.32 g of potassium persulfate are dissolved to prepare a mixed monomer aqueous solution with a concentration of 40%. 556 g of cyclohexane and sorbitan monostearate in a 2 volume flask
After dissolving 4.7 g and thoroughly purging with nitrogen, the mixed monomer aqueous solution was added dropwise and suspended while stirring. Furthermore
A polymer suspension is obtained by carrying out a polymerization reaction at 60°C for 3 hours. By evaporating this to dryness under reduced pressure, a finely granular water-absorbing resin powder according to the present invention is obtained. Table 2 shows the absorption capacity of each of the obtained resin powders.
Claims (1)
は水素原子、アルカリ金属原子又はアンモニウム
基を示す〕 で表わされる化合物、 (c) 一般式 〔式中R3は水素原子又はメチル基、M2は水素
原子、アルカリ金属原子又はアンモニウム基、Ｘ
は酸素原子又はイミノ基及びＹは炭素数２〜10の
直鎖状もしくは分岐鎖状アルキレン基を示す〕で
表わされる化合物、 及び (d)水混和性乃至水溶性ジビニル系化合物を構成
単量体として使用し、上記(a)成分、(b)成分及び(c)
成分の割合が30〜80、５〜55及び５〜25モル％で
あり、且つ(d)成分の割合が上記(a)成分、(b)成分及
び(c)成分の合計重量に対して0.001〜0.1重量％で
あることを特徴とする吸水性樹脂の製造法。 ２ 水混和性乃至水溶性ジビニル系化合物が、
Ｎ，Ｎ−メチレンビスアクリルアミド及びＮ，Ｎ
−メチレンビスメタクリルアミドから選択される
特許請求の範囲第１項に記載の製造法。 ３ (a)成分、(b)成分、(c)成分及び(d)成分を総単量
体濃度60〜85重量％の加温水溶液とし、これに重
合反応開始剤を添加して外部加熱を行なうことな
く重合反応させると共に水分を気化させて得られ
る特許請求の範囲第１項に記載の製造法。[Claims] 1 (a) General formula [In the formula, R 1 represents a hydrogen atom or a methyl group] A compound represented by (b) general formula [In the formula, R 2 represents a hydrogen atom or a methyl group, and M 1
represents a hydrogen atom, an alkali metal atom, or an ammonium group], (c) a compound represented by the general formula [In the formula, R 3 is a hydrogen atom or a methyl group, M 2 is a hydrogen atom, an alkali metal atom or an ammonium group,
is an oxygen atom or an imino group, and Y is a linear or branched alkylene group having 2 to 10 carbon atoms]; and (d) monomers constituting the water-miscible or water-soluble divinyl compound. Used as the above (a) component, (b) component and (c)
The proportion of the components is 30 to 80, 5 to 55 and 5 to 25 mol%, and the proportion of component (d) is 0.001 with respect to the total weight of the above components (a), (b) and (c). A method for producing a water absorbent resin characterized in that the content is ~0.1% by weight. 2 The water-miscible or water-soluble divinyl compound is
N,N-methylenebisacrylamide and N,N
-methylenebismethacrylamide. 3 Components (a), (b), (c) and (d) are made into a heated aqueous solution with a total monomer concentration of 60 to 85% by weight, a polymerization initiator is added to this, and external heating is applied. The manufacturing method according to claim 1, which is obtained by carrying out a polymerization reaction and vaporizing water without performing a polymerization reaction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58164871A JPS6055011A (en) | 1983-09-06 | 1983-09-06 | Water-absorptive resin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58164871A JPS6055011A (en) | 1983-09-06 | 1983-09-06 | Water-absorptive resin |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6055011A JPS6055011A (en) | 1985-03-29 |
| JPH0321562B2 true JPH0321562B2 (en) | 1991-03-25 |
Family
ID=15801507
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58164871A Granted JPS6055011A (en) | 1983-09-06 | 1983-09-06 | Water-absorptive resin |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6055011A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62144748A (en) * | 1985-12-18 | 1987-06-27 | Nippon Shokubai Kagaku Kogyo Co Ltd | Salt resistant water absorbent |
| JPH0188279U (en) * | 1987-11-28 | 1989-06-12 | ||
| KR970070032A (en) * | 1996-04-01 | 1997-11-07 | 성재갑 | Process for producing methacrylic polymer by suspension polymerization |
| JP4711122B2 (en) * | 2005-07-01 | 2011-06-29 | Ｄｉｃ株式会社 | Water absorbing material |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50114391A (en) * | 1974-02-01 | 1975-09-08 | ||
| JPS51125468A (en) * | 1975-03-27 | 1976-11-01 | Sanyo Chem Ind Ltd | Method of preparing resins of high water absorbency |
| JPS582312A (en) * | 1981-06-19 | 1983-01-07 | ケミツシユ・フアブリク・ストツクハウゼン・ゲ−エムベ−ハ− | Bridged copolymer and absorbent |
| JPS5832607A (en) * | 1981-08-20 | 1983-02-25 | Kao Corp | Preparation of water-absorbing material having improved water absorption property |
| JPS5922939A (en) * | 1982-07-08 | 1984-02-06 | カセラ・アクチエンゲゼルシヤフト | Bridging agent for water-swellable polymer and use |
-
1983
- 1983-09-06 JP JP58164871A patent/JPS6055011A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS50114391A (en) * | 1974-02-01 | 1975-09-08 | ||
| JPS51125468A (en) * | 1975-03-27 | 1976-11-01 | Sanyo Chem Ind Ltd | Method of preparing resins of high water absorbency |
| JPS582312A (en) * | 1981-06-19 | 1983-01-07 | ケミツシユ・フアブリク・ストツクハウゼン・ゲ−エムベ−ハ− | Bridged copolymer and absorbent |
| JPS5832607A (en) * | 1981-08-20 | 1983-02-25 | Kao Corp | Preparation of water-absorbing material having improved water absorption property |
| JPS5922939A (en) * | 1982-07-08 | 1984-02-06 | カセラ・アクチエンゲゼルシヤフト | Bridging agent for water-swellable polymer and use |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6055011A (en) | 1985-03-29 |
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