JPS6136763B2 - - Google Patents
Info
- Publication number
- JPS6136763B2 JPS6136763B2 JP4112579A JP4112579A JPS6136763B2 JP S6136763 B2 JPS6136763 B2 JP S6136763B2 JP 4112579 A JP4112579 A JP 4112579A JP 4112579 A JP4112579 A JP 4112579A JP S6136763 B2 JPS6136763 B2 JP S6136763B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- water
- surfactant
- parts
- alkali metal
- 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
Links
- 239000000178 monomer Substances 0.000 claims description 64
- 229920006037 cross link polymer Polymers 0.000 claims description 35
- 239000004094 surface-active agent Substances 0.000 claims description 34
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 claims description 32
- 229920000642 polymer Polymers 0.000 claims description 32
- -1 alkali metal salt Chemical class 0.000 claims description 30
- 238000004519 manufacturing process Methods 0.000 claims description 26
- 229910052783 alkali metal Inorganic materials 0.000 claims description 25
- 239000007864 aqueous solution Substances 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 20
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 claims description 19
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 19
- 238000001035 drying Methods 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 7
- 150000001340 alkali metals Chemical class 0.000 claims description 4
- 239000002736 nonionic surfactant Substances 0.000 claims description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 3
- 229910052708 sodium Inorganic materials 0.000 claims description 3
- 239000011734 sodium Substances 0.000 claims description 3
- 229940048053 acrylate Drugs 0.000 description 37
- 238000006116 polymerization reaction Methods 0.000 description 33
- 238000004132 cross linking Methods 0.000 description 22
- 230000008719 thickening Effects 0.000 description 19
- 239000000843 powder Substances 0.000 description 18
- 239000011347 resin Substances 0.000 description 18
- 229920005989 resin Polymers 0.000 description 18
- 239000002250 absorbent Substances 0.000 description 17
- 230000002745 absorbent Effects 0.000 description 17
- 238000010521 absorption reaction Methods 0.000 description 17
- 239000003960 organic solvent Substances 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 9
- 229920000742 Cotton Polymers 0.000 description 8
- 239000002585 base Substances 0.000 description 8
- 238000005520 cutting process Methods 0.000 description 8
- 239000006185 dispersion Substances 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 239000002562 thickening agent Substances 0.000 description 8
- 239000007788 liquid Substances 0.000 description 7
- 239000000499 gel Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 238000007334 copolymerization reaction Methods 0.000 description 5
- 239000000428 dust Substances 0.000 description 5
- 238000000465 moulding Methods 0.000 description 5
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 4
- 229920002125 Sokalan® Polymers 0.000 description 4
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 229920001577 copolymer Polymers 0.000 description 4
- 239000010419 fine particle Substances 0.000 description 4
- 238000010528 free radical solution polymerization reaction Methods 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 229920001495 poly(sodium acrylate) polymer Polymers 0.000 description 4
- 239000004584 polyacrylic acid Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- NNMHYFLPFNGQFZ-UHFFFAOYSA-M sodium polyacrylate Chemical compound [Na+].[O-]C(=O)C=C NNMHYFLPFNGQFZ-UHFFFAOYSA-M 0.000 description 4
- 150000005846 sugar alcohols Polymers 0.000 description 4
- 230000008961 swelling Effects 0.000 description 4
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 235000014113 dietary fatty acids Nutrition 0.000 description 3
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 239000000194 fatty acid Substances 0.000 description 3
- 229930195729 fatty acid Natural products 0.000 description 3
- 239000003999 initiator Substances 0.000 description 3
- 230000003472 neutralizing effect Effects 0.000 description 3
- 238000007127 saponification reaction Methods 0.000 description 3
- 229920001059 synthetic polymer Polymers 0.000 description 3
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 description 2
- IXPNQXFRVYWDDI-UHFFFAOYSA-N 1-methyl-2,4-dioxo-1,3-diazinane-5-carboximidamide Chemical compound CN1CC(C(N)=N)C(=O)NC1=O IXPNQXFRVYWDDI-UHFFFAOYSA-N 0.000 description 2
- LEJBBGNFPAFPKQ-UHFFFAOYSA-N 2-(2-prop-2-enoyloxyethoxy)ethyl prop-2-enoate Chemical compound C=CC(=O)OCCOCCOC(=O)C=C LEJBBGNFPAFPKQ-UHFFFAOYSA-N 0.000 description 2
- XFCMNSHQOZQILR-UHFFFAOYSA-N 2-[2-(2-methylprop-2-enoyloxy)ethoxy]ethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCOCCOC(=O)C(C)=C XFCMNSHQOZQILR-UHFFFAOYSA-N 0.000 description 2
- KUDUQBURMYMBIJ-UHFFFAOYSA-N 2-prop-2-enoyloxyethyl prop-2-enoate Chemical compound C=CC(=O)OCCOC(=O)C=C KUDUQBURMYMBIJ-UHFFFAOYSA-N 0.000 description 2
- DBCAQXHNJOFNGC-UHFFFAOYSA-N 4-bromo-1,1,1-trifluorobutane Chemical compound FC(F)(F)CCCBr DBCAQXHNJOFNGC-UHFFFAOYSA-N 0.000 description 2
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 2
- 108010010803 Gelatin Proteins 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 241001122767 Theaceae Species 0.000 description 2
- DAKWPKUUDNSNPN-UHFFFAOYSA-N Trimethylolpropane triacrylate Chemical compound C=CC(=O)OCC(CC)(COC(=O)C=C)COC(=O)C=C DAKWPKUUDNSNPN-UHFFFAOYSA-N 0.000 description 2
- JUDXBRVLWDGRBC-UHFFFAOYSA-N [2-(hydroxymethyl)-3-(2-methylprop-2-enoyloxy)-2-(2-methylprop-2-enoyloxymethyl)propyl] 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCC(CO)(COC(=O)C(C)=C)COC(=O)C(C)=C JUDXBRVLWDGRBC-UHFFFAOYSA-N 0.000 description 2
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000007865 diluting Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- STVZJERGLQHEKB-UHFFFAOYSA-N ethylene glycol dimethacrylate Substances CC(=C)C(=O)OCCOC(=O)C(C)=C STVZJERGLQHEKB-UHFFFAOYSA-N 0.000 description 2
- 238000004880 explosion Methods 0.000 description 2
- 235000013373 food additive Nutrition 0.000 description 2
- 239000002778 food additive Substances 0.000 description 2
- 239000008273 gelatin Substances 0.000 description 2
- 229920000159 gelatin Polymers 0.000 description 2
- 235000019322 gelatine Nutrition 0.000 description 2
- 235000011852 gelatine desserts Nutrition 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 229940047670 sodium acrylate Drugs 0.000 description 2
- 239000000661 sodium alginate Substances 0.000 description 2
- 235000010413 sodium alginate Nutrition 0.000 description 2
- 229940005550 sodium alginate Drugs 0.000 description 2
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- KOMNUTZXSVSERR-UHFFFAOYSA-N 1,3,5-tris(prop-2-enyl)-1,3,5-triazinane-2,4,6-trione Chemical compound C=CCN1C(=O)N(CC=C)C(=O)N(CC=C)C1=O KOMNUTZXSVSERR-UHFFFAOYSA-N 0.000 description 1
- HWSSEYVMGDIFMH-UHFFFAOYSA-N 2-[2-[2-(2-methylprop-2-enoyloxy)ethoxy]ethoxy]ethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCOCCOCCOC(=O)C(C)=C HWSSEYVMGDIFMH-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 101100008044 Caenorhabditis elegans cut-1 gene Proteins 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical class [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 239000002211 L-ascorbic acid Substances 0.000 description 1
- 235000000069 L-ascorbic acid Nutrition 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- VCUFZILGIRCDQQ-KRWDZBQOSA-N N-[[(5S)-2-oxo-3-(2-oxo-3H-1,3-benzoxazol-6-yl)-1,3-oxazolidin-5-yl]methyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical group O=C1O[C@H](CN1C1=CC2=C(NC(O2)=O)C=C1)CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F VCUFZILGIRCDQQ-KRWDZBQOSA-N 0.000 description 1
- 239000002202 Polyethylene glycol Substances 0.000 description 1
- 229920001214 Polysorbate 60 Polymers 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229930006000 Sucrose Natural products 0.000 description 1
- OKKRPWIIYQTPQF-UHFFFAOYSA-N Trimethylolpropane trimethacrylate Chemical compound CC(=C)C(=O)OCC(CC)(COC(=O)C(C)=C)COC(=O)C(C)=C OKKRPWIIYQTPQF-UHFFFAOYSA-N 0.000 description 1
- GQPVFBDWIUVLHG-UHFFFAOYSA-N [2,2-bis(hydroxymethyl)-3-(2-methylprop-2-enoyloxy)propyl] 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCC(CO)(CO)COC(=O)C(C)=C GQPVFBDWIUVLHG-UHFFFAOYSA-N 0.000 description 1
- CQHKDHVZYZUZMJ-UHFFFAOYSA-N [2,2-bis(hydroxymethyl)-3-prop-2-enoyloxypropyl] prop-2-enoate Chemical compound C=CC(=O)OCC(CO)(CO)COC(=O)C=C CQHKDHVZYZUZMJ-UHFFFAOYSA-N 0.000 description 1
- HVVWZTWDBSEWIH-UHFFFAOYSA-N [2-(hydroxymethyl)-3-prop-2-enoyloxy-2-(prop-2-enoyloxymethyl)propyl] prop-2-enoate Chemical compound C=CC(=O)OCC(CO)(COC(=O)C=C)COC(=O)C=C HVVWZTWDBSEWIH-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 239000003905 agrochemical Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 150000005215 alkyl ethers Chemical class 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 239000003945 anionic surfactant Substances 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 229960005070 ascorbic acid Drugs 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 238000012662 bulk polymerization Methods 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000003776 cleavage reaction Methods 0.000 description 1
- 239000002537 cosmetic Substances 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 239000011243 crosslinked material Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 238000004049 embossing Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 238000007720 emulsion polymerization reaction Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- CYKDLUMZOVATFT-UHFFFAOYSA-N ethenyl acetate;prop-2-enoic acid Chemical compound OC(=O)C=C.CC(=O)OC=C CYKDLUMZOVATFT-UHFFFAOYSA-N 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000003205 fragrance Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229920000578 graft copolymer Polymers 0.000 description 1
- 239000011346 highly viscous material Substances 0.000 description 1
- 238000003898 horticulture Methods 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 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
- 230000009257 reactivity Effects 0.000 description 1
- 239000012966 redox initiator Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000007017 scission Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000003516 soil conditioner Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Absorbent Articles And Supports Therefor (AREA)
Description
本発明は、アクリル酸アルカリ金属塩架橋重合
体の製造方法に関するものである。更に詳しく
は、製造時に有機溶剤を使用せず、ゲル状含水重
合体の取り扱いが容易で、しかも架橋重合体がす
でに中和されており、水性物質に接したときに優
れた初期吸収速度と高い粘性を示すアクリル酸ア
ルカリ金属塩架橋重合体の製造方法に関するもの
である。
近年、親水性合成高分子を吸収性樹脂又は増粘
性樹脂として使用する研究がなされている。この
ような吸収性樹脂は、使いすて紙おむつや生理綿
などの吸収材内部の一構成物として用いる試みが
なされている。従来、このような吸収性樹脂とし
ては、例えばデンプン−アクリロニトリルグラフ
ト重合体のケン化物、酢酸ビニル−アクリル酸エ
ステル共重合体のケン化物、アクリロニトリル系
共重合体の加水分解物、アクリルアミド系共重合
体の加水分解物等の重合体及び架橋体が検討され
ている。しかしながら、これらの吸収性樹脂は吸
収能において一部良好なものもあるが、いずれも
高粘性物質をケン化又は中和して製造するため生
産性が低く、且つ不純物が混入しやすいという重
大な欠点を有している。さらに、これらの吸収性
樹脂の製造にあたつて、いずれも重合・ケン化・
洗浄等の工程において有機溶剤が用いられている
という点でも大きな問題をかかえている。即ち、
重合溶媒として有機溶剤が用いられていると、突
発的な重合や重合熱の除去の失敗などから反応系
の温度や圧力が異常に上昇し、爆発火災が発生す
ることがある。また、洗浄・過・乾燥等の操作
時にも、有機溶剤が用いられていると爆発火災の
発生の危険及び作業員に対する毒性の問題があ
る。従つて工業的に生産する時の溶剤としては、
できるだけ水のみであることが好ましい。
一方、増粘性樹脂は、例えば湿布薬用増粘剤と
して用いられ、湿布薬基剤に増粘性、賦型性ある
いは保水性を持たせるために使われている。この
ような増粘性樹脂としては、アルギン酸ソーダ、
ゼラチン、カルボキシメチルセルロース等の天然
物又は半天然物、あるいはポリエチレングリコー
ル、ポリビニルアルコール等の合成高分子が用い
られている。しかし、これらはいずれも増粘性が
不充分で、保水性も悪いという欠点を有してい
る。
ところで、保水性及び増粘性に優れた合成高分
子として、ポリアクリル酸アルカリ金属塩が知ら
れている。中でもポリアクリル酸ソーダは食品添
加物として認可された安全性の高い高分子物質で
あり、工業的にも製造されている。しかしポリア
クリル酸アルカリ金属塩は、水系の被吸収液に接
したときに可溶性であるためベトつくことと、高
いPH値を呈することのために、皮膚に直接接する
用途に使用するには問題があつた。
このような、水系の被吸収液に接したときのベ
トつきや高いPH値を改良するために、ポリアクリ
ル酸を部分中和物とすることによりPH値を調節し
たり、ポリアクリル酸アルカリ金属塩を架橋せし
めてベトつきを少くする方法が提案されている。
例えば、特開昭52−127993号明細書には有機溶媒
中にアクリル酸、多官能性単量体及びアルカリを
同時に逐次添加して重合と架橋と中和を同時に行
わせしめる方法が開示されている。又、特開昭53
−46389号明細書には部分中和のアクリル酸アル
カリ金属塩を有機溶媒中で逆相乳化重合して自己
架橋型アクリル酸アルカリ金属塩ポリマーを得る
方法が開示されている。しかし、これらの方法は
すでに中和された架橋体を合成できるが、いずれ
も有機溶媒を用いることが必須であり、従つて、
前記した如き有機溶媒を用いることによる問題を
そのまま有している。
本発明者らにより、先に提案されたポリアクリ
ル酸アルカリ金属塩架橋体の製造方法（特願昭53
−156342号）に従えば、製造時に有機溶媒を使用
せず、水系被吸収液に接したときに優れた吸収能
と高い粘性を示し且つ皮膚に安全なPH値を呈する
親水性樹脂を製造でき好ましい。しかしこの方法
では製造時において、ゲル状含水重合体の粘着性
が大きいため重合容器からの離型性が悪い。更
に、ゲル状含水重合体を加熱乾燥するに際してカ
ツターにより細分化する時や押出機等により成型
する時に、ゲル状含水重合体の粘着性に起因して
作業性が悪い。又粘着性に起因する機械的な混練
を受けやすい結果、分子の切断等による物性の低
下のため吸収性や増粘性の低下があるという欠点
もある。また、この架橋体は水性物質と接した時
に吸収倍率は大きいが、初期吸収速度がやや低い
という欠点も有している。
一方、アクリル酸塩やアクリル酸部分中和物を
水溶液重合するに際し、架橋剤としてエチレング
リコールジメタクリレートやトリメチロールプロ
パントリアクリレートなどの架橋性単量体を添加
することによりポリアクリル酸塩やポリアクリル
酸部分中和物を架橋する方法が提案されている。
しかしこのような方法では、これらの架橋性単量
体とアクリル酸塩水溶液やアクリル酸部分中和物
水溶液との相溶性が悪く、均一な共重合架橋体が
得られにくい。さらに、得られるゲル状含水重合
体の粘着性が大きく、そのため重合容器からの離
型やその後の切断、押出などの工程が困難とな
る。
本発明者らは、従来知られている吸収性樹脂及
び増粘性樹脂の有している上記の如き種種の問題
を解決すべく鋭意研究を重ねた結果、水溶性及
び／又は水分散性界面活性剤の存在下、架橋性単
量体(B)及びアクリル酸塩系単量体(A)を比較的高濃
度で水溶液共重合して得たアクリル酸アルカリ金
属塩架橋重合体が、従来の吸収性樹脂及び増粘性
樹脂の有する上記の如き種々の問題をことごとく
解決するものであることを見出して本発明を完成
するに至つたものである。
従つて、本発明の目的は、吸収性及び増粘性に
優れ、被吸収液と接したときにもベトつきがな
く、しかも人体の皮膚に対して安全な範囲にPH調
節することができ、吸収性樹脂及び増粘性樹脂と
して好適なアクリル酸アルカリ金属塩架橋重合体
（以下、単に架橋重合体という。）を有機溶媒を使
用することなくしかも作業性よく製造する方法を
提供するものである。
即ち、第１の発明は、水溶性及び／又は水分散
性界面活性剤の存在下、アクリル酸０〜50モル％
とアクリル酸アルカリ金属塩50〜100モル％とか
らなるアクリル酸塩系単量体(A)100重量部と架橋
性単量体(B)0.001〜５重量部との混合物を25重量
％以上の濃度で水溶液共重合することを特徴とす
るものである。
また、第２の発明は、水溶性及び／又は水分散
性界面活性剤の存在下、アクリル酸０〜50モル％
とアクリル酸アルカリ金属塩50〜100モル％とか
らなるアクリル酸塩系単量体(A)100重量部と架橋
性単量体(B)0.001〜５重量部との混合物を25重量
％以上の濃度で水溶液共重合して得られたゲル状
含水重合体を加熱乾燥することを特徴とするもの
である。
本発明において使用される水溶性又は水分散性
界面活性剤は、アクリル酸塩系単量体(A)水溶液と
相溶するかあるいは分散する事が必要である。そ
のような界面活性剤として、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ルキル
フエノールエーテル、ソルビタン脂肪酸エステ
ル、ポリオキシエチレンソルビタン脂肪酸エステ
ル、ポリオキシエチレンアシルエステル、オキシ
エチレンオキシプロピレンブロツク共重合体、シ
ヨ糖脂肪酸エステル、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エート塩等の非イオン系
界面活性剤あるいは陰イオン系界面活性剤の中か
ら選ばれた１種又は２種以上を用いることができ
る。中でも、本発明では水溶性又は水分散性で
HLBが７以上の非イオン系界面活性剤が特に好
ましい。本発明に用いられる水溶性及び／又は水
分散性界面活性剤の使用量は、アクリル酸塩系単
量体(A)100重量部に対して0.01〜10重量部の範囲
の比率の量である事が好ましい。水溶性及び／又
は水分散性界面活性剤の使用量が0.01重量部未満
の少ない量では、アクリル酸塩系単量体(A)水溶液
と架橋性単量体(B)との相溶性が悪く、均一な架橋
重合体が得られない。しかも得られるゲル状含水
重合体の粘着性が大きく、そのため重合容器から
の離型が困難である。又、切断時あるいは押出機
等による成型時の作業性も悪い。さらに、ゲル状
含水重合体を加熱乾燥後、粉体とした場合に、水
性物質に対する初期吸収速度が小さい。逆に10重
量部を超える量では、重合時に界面活性剤に対す
る連鎖移動により架橋重合体の分子量が小さくな
つて、得られるゲル状含水重合体が柔かく、取り
扱い困難となる。また、加熱乾燥後粉体とした場
合に水性物質と接した時の吸収能が低下する。
水溶性及び／又は水分散性界面活性剤は、重合
前にはアクリル酸塩系単量体(A)水溶液に完全に溶
解しているか、又は細かく乳化分散している。そ
してアクリル酸塩系単量体(A)水溶液に対して相溶
性の悪い架橋性単量体(B)をアクリル酸塩系単量体
(A)水溶液中に可溶化し、アクリル酸塩系単量体(A)
と架橋性単量体(B)との共重合反応性を高めて均一
な架橋を行わせしめる作用を有している。このよ
うな界面活性剤は、重合が進行するに従つて、生
成するゲル状の含水重合体の中で相分離して乳白
状に均一に分散した状態になる。そして、得られ
た含水重合体の表面及び内部には、界面活性剤の
微粒子又は微液滴が存在している。このため含水
重合体が接触する重合容器への密着が少なくな
り、離型性は大巾に改良される。さらに、ゲル状
含水重合体を切断あるいは成型する時に金属製の
カツター、ニーダー、スクリユーあるいはノズル
等に接触したり、切断等により新たな切断破断面
を形成しても、界面活性剤の微粒子又は微液滴が
含水重合体の内部に均一に存在しているため常に
離型性がよいという利点を有している。
本発明で用いられるアクリル酸塩系単量体(A)
は、アクリル酸０〜50モル％とアクリル酸アルカ
リ金属塩50〜100モル％とからなるものである。
アクリル酸アルカリ金属塩の割合が50モル％未満
であると、得られるゲル状含水重合体の粘着性が
大きいため、重合容器からの離型性が悪く、切断
あるいは押出機等による成型時の取り扱いが困難
となる。本発明で用いられるアクリル酸塩系単量
体(A)はアクリル酸アルカリ金属塩の割合が100モ
ル％でも差し支えない。また、必要ならばアクリ
ル酸を中和するためのアルカリ金属水酸化物等の
塩基が、アクリル酸に対して等モル以上の比率で
使用されている場合でもよい。アクリル酸塩水溶
液の重合性は、アクリル酸の中和率が高いほど良
いが、得られる架橋重合体が水系の被吸収液と接
した時や水分散体とした時のPHが人体の皮膚に対
して安全な範囲になるように考慮するならば、ア
クリル酸塩系単量体(A)中に占めるアクリル酸アル
カリ金属塩の割合は60〜90モル％が好ましい。
本発明で用いるアクリル酸は、市販のものを用
いることができる。又、必要に応じてアクリル酸
の一部を、例えばメタクリル酸の様な他の水溶性
の重合性カルボン酸で置き換えることもできる。
アルカリ金属としては、リチウム、ナトリウ
ム、カリウム等通常用いられるものを使用するこ
とができる。特にナトリウムは、ポリアクリル酸
ソーダが食品添加物として認められており、安全
性の点から好ましい。
本発明で用いる架橋性単量体(B)は、一分子中に
少くとも２個の重合性二重結合を有し、アクリル
酸塩系単量体(A)及び界面活性剤と水溶媒中で相溶
し、しかもアクリル酸塩系単量体(A)と共重合性が
良くて効率よく架橋構造をとりうることが必須で
ある。そのような架橋性単量体としては、エチレ
ングリコールジアクリレート、エチレングリコー
ルジメタアクリレート、ジエチレングリコールジ
アクリレート、ジエチレングリコールジメタアク
リレート、トリエチレングリコールジアクリレー
ル、トリエチレングリコールジメタアクリレー
ト、トリメチロールプロパントリアクリレート、
トリメチロールプロパントリメタアクリレート、
ペンタエリスリトールトリアクリレート、ペンタ
エリスリトールトリメタアクリレート、Ｎ・
N′−メチレンビスアクリルアミド、イソシアヌ
ル酸トリアリル、ペンタエリスリトールジアクリ
レート、ペンタエリスリトールジメタアクリレー
トなどの中から選ばれた１種又は２種以上を用い
る事ができる。
本発明に用いられる架橋性単量体(B)の使用量
は、アクリル酸塩系単量体(A)100重量部に対して
0.001〜５重量部の範囲の比率の量であることが
必要である。この範囲内の量であれば、架橋性単
量体(B)の使用量が多い程架橋重合体の架橋密度が
大きくなり、架橋重合体を水溶液あるいは水分散
液としたときの増粘性が大きくなる。しかし５重
量部を超える量では架橋密度が大きくなりすぎ
て、かえつて増粘性及び吸収能が低下する。逆に
0.001重量部未満の少い量では架橋密度が小さす
ぎて増粘性が低く、被吸収液と接したときにベル
トつきが生じ、初期吸収速度も低い。本発明の製
造方法では、アクリル酸塩系単量体(A)100重量部
に対して架橋性単量体(B)の使用量は0.001〜５重
量部であり、このように比較的少量の架橋性単量
体(B)の使用でも、界面活性剤の併用と高濃度での
水溶液共重合とによりアクリル酸塩系単量体(A)と
均一に効率よく共重合し、均一な架橋構造の架橋
重合体が得られるのである。
本発明の製造方法に従つて水溶液共重合するに
際し、重合に先だつてアクリル酸塩系単量体(A)、
架橋性単量体(B)及び界面活性剤は通常の方法で混
合され、又いかなる順序で混合されてもよい。ま
た、必要に応じて他の成分を添加して併用するこ
ともできる。このような他の成分としては例えば
ジエチレングリコールやグリセリンのような多価
アルコールを挙げることができる。本発明におい
て、アクリル酸塩系単量体(A)中に占めるアクリル
酸アルカリ金属塩の割合が100モル％未満で、ア
クリル酸に基づくカルボキシル基が存在すると
き、このような多価アルコールを併用するなら、
得られるゲル状含水重合体を加熱乾燥する段階で
重合体中のカルボキシル基と多価アルコールとの
反応による架橋も行なわれる。即ち、架橋重合体
中に、架橋性単量体(B)による架橋と多価アルコー
ルによる架橋とを併存させることも可能である。
本発明に採用される水溶液重合の方法として
は、アクリル酸塩系単量体(A)、架橋性単量体(B)、
水溶性及び／又は水分散性界面活性剤並びに開始
剤が均一に混合され且つアクリル酸塩系単量体(A)
と架橋性単量体(B)との混合物を25重量％以上の濃
度で含有する水溶液又は水分散液を窒素雰囲気下
で塊状重合又は注型重合する方法が好ましい。そ
して重合による発熱を除去し、反応温度の調節を
容易にするためには、比較的伝熱面積の大きい密
閉容器で重合することが好ましい。このような水
溶液重合のためには、たとえば特公昭48−42466
号明細書に記載の重合容器が好適である。重合時
のモノマー濃度が25重量％未満の時は架橋重合体
の分子量が高くなりにくく、従つて得られる含水
重合体がやわらかいゲル状となり、取り扱いが困
難となる。
水溶液重合に用いられる開始剤は、通常の水溶
性ラジカル発生開始剤であれば特に制限はない。
たとえば過硫酸アンモン、過硫酸カリ、過酸化水
素等が挙げられ、又これらと亜硫酸水素ナトリウ
ム、ｌ−アスコルビン酸、第１鉄塩等の還元剤と
の組みあわせによるレドツクス系開始剤も用いら
れる。
重合時の重合温度としては、比較的低温の方が
得られる架橋重合体の分子量が大きくなり好まし
いが、重合が完結するためには10℃以上80℃以下
の範囲内であることが好ましい。
本発明の製造方法に基づいて水溶液共重合によ
り得られた架橋重合体のゲル状含水重合体を加熱
乾燥するに際しては、過度の熱による劣化を防ぐ
ためできるだけ効率よく短時間で乾燥する事が望
ましい。この様な乾燥方法として、ゲル状含水重
合体を切断あるいは押出し等によつて単位体積当
りの表面積が９cm2/cm3以上になるように細分化し
たのち、100〜230℃の温度の熱風で加熱して乾燥
する方法が特に好ましい。
本発明の製造方法に対して、界面活性剤を用い
ないでアクリル酸塩系単量体(A)と架橋性単量体(B)
との混合水溶液を重合させたのち、ゲル状含水重
合体の段階で界面活性剤を添加したのでは、アク
リル酸塩系単量体(A)と架橋性単量体(B)との均一な
共重合架橋を行なわせる事は出来ない。またゲル
状含水重合体の内部まで界面活性剤が均一に分布
する事は不可能であり、従つて切断あるいは押出
時の粘着を防止する事は不可能である。さらに、
得られる架橋重合体を粉体化しても、このような
粉体中には界面活性剤が均一に分布しておらず、
発塵性の改良や、水性物質に接した時の「まま
こ」発生防止の効果は期待できない。
このようにして本発明の製造方法に基づいて得
られた架橋重合体は、必要に応じて粉砕して粉体
として用いられる。粉砕の方法としては特に制限
はなく、従来公知の方法を適宜用いることができ
る。本発明に基づけば、ゲル状含水重合体を加熱
乾燥したのちも乾燥物表面及び内部に界面活性剤
の微粒子又は微液滴が均一に分散しているため、
容易に、短時間で粉砕し得る。又、この粉砕工程
で微粉末が生成しても、粒子表面及び内部に均一
に分散して存在している界面活性剤の微粒子又は
微液滴のために、微粉末は軽度に凝集し易く、従
つて粉塵がたたないという利点を有している。
このようにして本発明の製造方法に基づいて得
られた架橋重合体は、粉体化したのち吸収性樹脂
として使用されると、特に初期吸収性に優れた高
い吸収能を示す。これは、本発明の製法に基づく
架橋重合体が架橋性単量体(B)により均一に架橋さ
れているのに加えて、粉体粒子表面に比較的疎水
性の部分を有する界面活性剤の微粒子又は微液滴
が分散しているので水性物質と接触した場合にい
わゆる「ままこ」の状態になるのが防止され、従
つて水性物質は短時間に各重合体粒子に浸透し、
その後膨潤が行なわれるためと考えられる。
又、増粘性樹脂として使用されると、水等の分
散媒に分散させる時に「ままこ」が形成されるの
を防止する効果が大きく、均一分散が短時間に行
える利点を有している。
本発明の製造方法に基づいて得られた架橋重合
体は、吸収性及び増粘性に優れ、被吸収液と接し
たときにもベトつきがなく且つ吸収後の保持性も
良好で、しかも人体の皮膚に対して安全な範囲の
PHに調節することができる。従つて、使い捨て紙
おむつや生理綿の吸収部材、湿布薬の増粘剤、芳
香剤ゲルの増粘剤、化粧品分野やトイレタリー分
野の乳化安定剤及び増粘剤、カーペツトバツキン
グ剤や水系塗料の増粘剤、農薬の展着剤あるいは
土壌と混合して保水性を高める事による農業用や
園芸用の土質改良剤等として広い用途に使用され
得るものである。本発明の製造方法は、このよう
に優れた物性を有する架橋重合体を有機溶剤を用
いることなく、ケン化や洗浄等の煩雑な工程を必
要とせず、重合容器に対する粘着も乾燥のための
切断や成形時の粘着もなく、生産性良く製造する
方法を提供するものである。
以下、本発明の製造方法を実施例及び比較例に
より更に詳しく説明するが、本発明の範囲がこれ
らの例により限定されるものではない。尚、実施
例及び比較例中の％は特に断りのない限り重量％
を、又部は重量部を意味するものとする。
実施例 １
内面を４フツ化エチレン樹脂でライニングした
SUS304製で300mm×300mm×50mmの内容積をもつ
開閉可能な密閉容器に、アクリル酸ナトリウム75
モル％とアクリル酸25モル％とからなるアクリル
酸塩系単量体(A)の水溶液4000ｇ（モノマー濃度43
％）と第１表に示した量の各種架橋性単量体(B)及
び界面活性剤とを入れ、窒素雰囲気下で液温を40
℃としたあと、過硫酸アンモニウム0.6ｇ及び亜
硫酸水素ナトリウム0.2ｇを添加し均一に溶解し
た。重合はおだやかに進行し、発熱とともに白濁
したゲル状となつた。反応系の温度は重合開始後
２〜５時間に55〜80℃となつた。
重合開始７時間ののち密閉容器を開き、生成し
たゲル状含水重合体を取り出した。いずれのゲル
状含水重合体も重合容器から容易に離型した。取
り出したそれぞれのゲル状含水重合体を鋼鉄製カ
ツターで１cm角に切断したが、この切断工程にお
いてもカツターへの付着が全くなく、作業性は良
好であつた。
次に、切断された１cm角のゲル状含水重合体
を、それぞれ接触部がSUS316製で、スクリユー
径30mm、Ｌ／Ｄ＝17、スクリユー回転数45rpmの
スクリユー式押出機を用いて1.5mm径の多孔盤ノ
ズルから押出し、直径約２mmのひも状のゲルとし
た。このひも状のゲルの単位体積当りの表面積は
約20cm2/cm3であつた。このひも状のゲルを熱風乾
燥機中180℃で90分間乾燥し、アクリル酸アルカ
リ金属塩架橋重合体（架橋重合体(1)〜(4)）を得
た。
得られた各架橋重合体を振動式粉砕機で粉体と
した。この粉体0.2ｇを不織布製のテイーバツク
式袋（40mm×150mm）に均一に入れ、0.9％食塩水
に浸漬し、３分後及び５分後の重量をそれぞれ測
定した。テイーバツク式袋のみの吸収重量をブラ
ンクとし、次式に従つて架橋重合体の膨潤倍率を
求めた。
膨潤倍率＝吸収後の重量（ｇ）−ブランク（ｇ）／粉体
の重量（ｇ）
また得られた粉体20ｇを100mlのガラス製サンプ
ル瓶に入れ、一定時間振盪後、発塵性を調べた。
次にそれぞれの架橋体の粉体の１％水分散液の
粘度をＢ型粘度計（25℃、12rpm）で測定した。
結果を第１表に示した。
本発明の方法に基づいて得られた架橋重合体は
いずれもすぐれた初期吸収性を示し、しかも膨潤
ゲルはベトつきがなかつた。また発塵性もほとん
どなく、さらにいずれの架橋重合体も水分散液の
粘度が大きく、すぐれた増粘性を示した。また、
これらの架橋重合体の１％水分散液のPHはいずれ
も7.0であり、市販の高分子量ポリアクリル酸ソ
ーダの１％水溶液のPHが9.6であるのにくらべて
人体の皮膚に安全なPH値を示した。
比較例 １
架橋性単量体(B)を用いない他は実施例１と同様
にして重合体（比較重合体(1)）を得た。この比較
重合体(1)は粉体としたあとも可溶物が多く、吸収
剤としては不適であり、又第１表に示した如く粘
性も小さく、増粘剤としても不適であつた。
比較例 ２
界面活性剤を用いない他は実施例１と同様にし
て重合体（比較重合体(2)）を得た。この比較重合
体(2)は重合前の段階で架橋性単量体が均一に溶解
せず、また重合後の段階で重合容器への粘着性が
大きく、離型が困難であつた。さらに得られた粉
体の発塵性も大きかつた。
比較例 ３
アクリル酸塩系単量体(A)中のアクリル酸ナトリ
ウムの割合を40モル％、架橋性単量体(B)としてペ
ンタエリスリトールトリメタアクリレートの添加
率を0.1部（対モノマー100部）とし、界面活性剤
として花王アトラス(株)製“ネオペレツクス 05”
を１部（対モノマー100部）用いる以外は実施例
１と同様にして重合を試みた。しかし重合が開始
しないため、系の温度を60℃にしたところ急激な
重合がおこつた。得られた含水重合体は非常に柔
らかくて粘着性が大きく、重合容器からの離型性
が悪かつた。また実施例１と同様にして得た粉体
の0.9％食塩水の膨潤倍率を測定すると３分で24
倍、５分で26倍と小さな値を示した。
The present invention relates to a method for producing an alkali metal acrylate crosslinked polymer. More specifically, no organic solvents are used during production, the gel-like hydropolymer is easy to handle, and the crosslinked polymer is already neutralized, resulting in an excellent initial absorption rate and high speed when it comes into contact with aqueous substances. The present invention relates to a method for producing an alkali metal acrylate crosslinked polymer exhibiting viscosity. In recent years, research has been conducted on the use of hydrophilic synthetic polymers as absorbent resins or thickening resins. Attempts have been made to use such absorbent resins as a component inside absorbent materials such as disposable disposable diapers and sanitary cotton. Conventionally, such absorbent resins include, for example, saponified products of starch-acrylonitrile graft polymers, saponified products of vinyl acetate-acrylic acid ester copolymers, hydrolyzed products of acrylonitrile-based copolymers, and acrylamide-based copolymers. Polymers and crosslinked products such as hydrolysates of However, although some of these absorbent resins have good absorption capacity, they all have low productivity because they are manufactured by saponifying or neutralizing highly viscous substances, and they have the serious problem of being easily contaminated with impurities. It has drawbacks. Furthermore, in producing these absorbent resins, polymerization, saponification,
Another major problem is that organic solvents are used in cleaning and other processes. That is,
When an organic solvent is used as a polymerization solvent, the temperature and pressure of the reaction system may rise abnormally due to sudden polymerization or failure to remove the heat of polymerization, which may lead to explosions and fires. Furthermore, if organic solvents are used during cleaning, over-drying, drying, etc., there is a risk of explosion and fire and toxicity to workers. Therefore, as a solvent for industrial production,
It is preferable to use only water as much as possible. On the other hand, thickening resins are used, for example, as thickeners for medicinal poultices, and are used to impart thickening properties, shaping properties, or water retention properties to poultice drug bases. Such thickening resins include sodium alginate,
Natural or semi-natural products such as gelatin and carboxymethyl cellulose, or synthetic polymers such as polyethylene glycol and polyvinyl alcohol are used. However, all of these have the drawbacks of insufficient thickening properties and poor water retention. By the way, polyacrylic acid alkali metal salts are known as synthetic polymers with excellent water retention and thickening properties. Among them, sodium polyacrylate is a highly safe polymeric substance that has been approved as a food additive and is also manufactured industrially. However, polyacrylic acid alkali metal salts are soluble and sticky when they come into contact with aqueous absorbent liquids, and exhibit a high pH value, so there are problems when using them for applications that come in direct contact with the skin. It was hot. In order to improve the stickiness and high PH value when it comes into contact with water-based absorbed liquids, we can adjust the PH value by partially neutralizing polyacrylic acid, or use alkali metal polyacrylate. A method has been proposed to reduce stickiness by crosslinking salt.
For example, JP-A-52-127993 discloses a method in which acrylic acid, a polyfunctional monomer, and an alkali are simultaneously and sequentially added to an organic solvent to simultaneously perform polymerization, crosslinking, and neutralization. . Also, JP-A-53
No. 46389 discloses a method for obtaining a self-crosslinking type alkali metal acrylic salt polymer by subjecting a partially neutralized alkali metal acrylate to reverse phase emulsion polymerization in an organic solvent. However, although these methods can synthesize already neutralized crosslinked products, they all require the use of organic solvents, and therefore,
There are still problems caused by using organic solvents as described above. The method for producing a crosslinked alkali metal salt of polyacrylic acid previously proposed by the present inventors (Japanese Patent Application No. 53)
-156342), it is possible to produce a hydrophilic resin that exhibits excellent absorption capacity and high viscosity when in contact with aqueous absorbent liquids, and exhibits a pH value that is safe for the skin, without using organic solvents during production. preferable. However, in this method, during production, the adhesiveness of the gel-like hydrous polymer is high, resulting in poor releasability from the polymerization container. Furthermore, when drying a gel-like hydrous polymer by heating, workability is poor when dividing it into pieces using a cutter or molding it using an extruder or the like due to the stickiness of the gel-like hydrous polymer. In addition, as a result of being susceptible to mechanical kneading due to its tackiness, it also has the disadvantage of a decrease in absorbency and thickening ability due to a decrease in physical properties due to molecular cleavage and the like. Furthermore, although this crosslinked material has a high absorption capacity when it comes into contact with an aqueous substance, it also has the drawback that its initial absorption rate is rather low. On the other hand, when aqueous solution polymerization of acrylates and acrylic acid partially neutralized products, crosslinking monomers such as ethylene glycol dimethacrylate and trimethylolpropane triacrylate are added as crosslinking agents. A method of crosslinking partially neutralized acids has been proposed.
However, in such a method, the compatibility between these crosslinking monomers and an aqueous acrylate solution or an aqueous solution of partially neutralized acrylic acid is poor, making it difficult to obtain a uniform crosslinked copolymer. Furthermore, the resulting gel-like hydropolymer has high stickiness, which makes it difficult to release it from the polymerization container and to perform subsequent steps such as cutting and extrusion. The present inventors have conducted intensive research to solve the above-mentioned problems of conventionally known absorbent resins and thickening resins, and have found that water-soluble and/or water-dispersible surfactant An alkali metal acrylic salt crosslinked polymer obtained by copolymerizing a crosslinkable monomer (B) and an acrylate monomer (A) in a relatively high concentration in an aqueous solution in the presence of a conventional absorption agent The present invention was completed based on the discovery that the above-mentioned problems of thickening resins and thickening resins can be solved. Therefore, the object of the present invention is to provide an absorbent material that has excellent absorbency and thickening properties, does not become sticky even when it comes into contact with absorbed liquids, and can adjust the pH to a range that is safe for human skin. The present invention provides a method for producing an alkali metal acrylate crosslinked polymer (hereinafter simply referred to as a crosslinked polymer) suitable as a thickening resin and a thickening resin without using an organic solvent and with good workability. That is, the first invention provides 0 to 50 mol% of acrylic acid in the presence of a water-soluble and/or water-dispersible surfactant.
A mixture of 100 parts by weight of an acrylate monomer (A) consisting of 50 to 100 mol% of an alkali metal salt of acrylic acid and 0.001 to 5 parts by weight of a crosslinking monomer (B) in an amount of 25% by weight or more It is characterized by aqueous solution copolymerization at a certain concentration. Further, the second invention provides 0 to 50 mol% of acrylic acid in the presence of a water-soluble and/or water-dispersible surfactant.
A mixture of 100 parts by weight of an acrylate monomer (A) consisting of 50 to 100 mol% of an alkali metal salt of acrylic acid and 0.001 to 5 parts by weight of a crosslinking monomer (B) in an amount of 25% by weight or more This method is characterized by heating and drying a gel-like hydropolymer obtained by copolymerizing with an aqueous solution at a high concentration. The water-soluble or water-dispersible surfactant used in the present invention needs to be compatible with or disperse in the aqueous solution of the acrylate monomer (A). Such surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenol ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene acyl ester, oxyethylene oxypropylene block copolymer, and sucrose fatty acid. One or more types selected from nonionic surfactants or anionic surfactants such as esters, higher alcohol sulfate ester salts, alkylbenzene sulfonates, or polyoxyethylene sulfate salts can be used. can. Among these, in the present invention, water-soluble or water-dispersible
Particularly preferred are nonionic surfactants with an HLB of 7 or more. The amount of the water-soluble and/or water-dispersible surfactant used in the present invention is in the range of 0.01 to 10 parts by weight per 100 parts by weight of the acrylate monomer (A). Things are good. If the amount of water-soluble and/or water-dispersible surfactant used is small, such as less than 0.01 part by weight, the compatibility between the aqueous solution of acrylate monomer (A) and crosslinkable monomer (B) will be poor. , a uniform crosslinked polymer cannot be obtained. Moreover, the gel-like hydrous polymer obtained has a high stickiness, which makes it difficult to release it from the polymerization container. Moreover, the workability during cutting or molding using an extruder or the like is also poor. Furthermore, when the gel-like hydrous polymer is heated and dried and then made into powder, the initial absorption rate for aqueous substances is low. On the other hand, if the amount exceeds 10 parts by weight, the molecular weight of the crosslinked polymer decreases due to chain transfer to the surfactant during polymerization, and the resulting gel-like hydrous polymer becomes soft and difficult to handle. Moreover, when it is made into a powder after being heated and dried, its absorption capacity is reduced when it comes into contact with an aqueous substance. The water-soluble and/or water-dispersible surfactant is completely dissolved or finely emulsified and dispersed in the aqueous solution of the acrylate monomer (A) before polymerization. Then, the crosslinking monomer (B), which has poor compatibility with the acrylate monomer (A) aqueous solution, is added to the acrylate monomer (A).
(A) Solubilized in aqueous solution, acrylate monomer (A)
It has the effect of increasing the copolymerization reactivity between the monomer and the crosslinking monomer (B), and causing uniform crosslinking. As the polymerization progresses, such a surfactant undergoes phase separation in the resulting gel-like water-containing polymer and becomes uniformly dispersed in a milky white state. Fine particles or droplets of the surfactant are present on the surface and inside of the obtained hydrous polymer. Therefore, the adhesion of the hydrous polymer to the polymerization vessel with which it comes into contact is reduced, and the mold releasability is greatly improved. Furthermore, when cutting or molding a gel-like hydropolymer, if it comes into contact with a metal cutter, kneader, screw, or nozzle, or if a new cut surface is formed by cutting, fine surfactant particles or Since the droplets are uniformly present inside the water-containing polymer, it has the advantage of always having good mold releasability. Acrylate monomer (A) used in the present invention
is composed of 0 to 50 mol% of acrylic acid and 50 to 100 mol% of an alkali metal acrylate.
If the proportion of the alkali metal acrylic acid salt is less than 50 mol%, the gel-like hydrous polymer obtained will have high stickiness and will have poor releasability from the polymerization container, making it difficult to handle during cutting or molding with an extruder, etc. becomes difficult. The acrylate monomer (A) used in the present invention may have an alkali metal acrylate content of 100 mol%. Furthermore, if necessary, a base such as an alkali metal hydroxide for neutralizing acrylic acid may be used in an equimolar or more ratio to acrylic acid. The higher the neutralization rate of acrylic acid, the better the polymerizability of an acrylate aqueous solution, but the pH of the resulting crosslinked polymer when it comes into contact with an aqueous absorbing liquid or when it is made into an aqueous dispersion may be too high for human skin. Considering that it is within a safe range, the proportion of the alkali metal acrylate in the acrylate monomer (A) is preferably 60 to 90 mol%. As the acrylic acid used in the present invention, commercially available acrylic acid can be used. Also, if necessary, a part of the acrylic acid can be replaced with another water-soluble polymerizable carboxylic acid such as methacrylic acid. As the alkali metal, commonly used ones such as lithium, sodium, potassium, etc. can be used. In particular, sodium polyacrylate is approved as a food additive, and is preferable from the viewpoint of safety. The crosslinkable monomer (B) used in the present invention has at least two polymerizable double bonds in one molecule, and is mixed with the acrylate monomer (A) and a surfactant in an aqueous solvent. It is essential that the monomer is compatible with the acrylate monomer (A), has good copolymerizability with the acrylate monomer (A), and can efficiently form a crosslinked structure. Such crosslinking monomers include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacryl, triethylene glycol dimethacrylate, trimethylolpropane triacrylate. ,
trimethylolpropane trimethacrylate,
Pentaerythritol triacrylate, pentaerythritol trimethacrylate, N.
One or more selected from N'-methylenebisacrylamide, triallyl isocyanurate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, etc. can be used. The amount of the crosslinkable monomer (B) used in the present invention is based on 100 parts by weight of the acrylate monomer (A).
A proportionate amount in the range 0.001 to 5 parts by weight is required. If the amount is within this range, the greater the amount of crosslinkable monomer (B) used, the greater the crosslinking density of the crosslinked polymer, and the greater the viscosity increase when the crosslinked polymer is made into an aqueous solution or dispersion. Become. However, if the amount exceeds 5 parts by weight, the crosslinking density will become too high, and the thickening property and absorption capacity will deteriorate. vice versa
If the amount is less than 0.001 part by weight, the crosslinking density is too low and the thickening property is low, causing belting when it comes into contact with the liquid to be absorbed, and the initial absorption rate is also low. In the production method of the present invention, the amount of the crosslinking monomer (B) used is 0.001 to 5 parts by weight per 100 parts by weight of the acrylate monomer (A). Even when crosslinking monomer (B) is used, it can be uniformly and efficiently copolymerized with acrylate monomer (A) by using a surfactant in combination and copolymerizing with aqueous solution at high concentration, resulting in a uniform crosslinked structure. A crosslinked polymer is obtained. When performing aqueous solution copolymerization according to the production method of the present invention, prior to polymerization, acrylate monomer (A),
The crosslinkable monomer (B) and the surfactant are mixed in a conventional manner and may be mixed in any order. Moreover, other components can be added and used in combination as necessary. Examples of such other components include polyhydric alcohols such as diethylene glycol and glycerin. In the present invention, when the proportion of alkali metal acrylate in the acrylate monomer (A) is less than 100 mol% and a carboxyl group based on acrylic acid is present, such a polyhydric alcohol may be used in combination. If you do,
At the stage of drying the resulting gel-like hydrous polymer by heating, crosslinking is also carried out through the reaction of the carboxyl groups in the polymer with the polyhydric alcohol. That is, it is also possible to cause crosslinking by the crosslinkable monomer (B) and crosslinking by polyhydric alcohol to coexist in the crosslinked polymer. The aqueous solution polymerization method adopted in the present invention includes acrylate monomer (A), crosslinkable monomer (B),
The water-soluble and/or water-dispersible surfactant and the initiator are uniformly mixed, and the acrylate monomer (A)
A preferred method is to carry out bulk polymerization or cast polymerization in a nitrogen atmosphere of an aqueous solution or aqueous dispersion containing a mixture of the crosslinkable monomer (B) and the crosslinkable monomer (B) at a concentration of 25% by weight or more. In order to eliminate heat generated by polymerization and to easily control the reaction temperature, it is preferable to carry out the polymerization in a closed container with a relatively large heat transfer area. For such aqueous solution polymerization, for example, Japanese Patent Publication No. 48-42466
The polymerization vessel described in the above specification is suitable. When the monomer concentration during polymerization is less than 25% by weight, the molecular weight of the crosslinked polymer is difficult to increase, and the resulting hydrous polymer becomes soft and gel-like, making it difficult to handle. The initiator used in the aqueous solution polymerization is not particularly limited as long as it is a common water-soluble radical generating initiator.
Examples include ammonium persulfate, potassium persulfate, hydrogen peroxide, etc., and redox initiators made by combining these with reducing agents such as sodium bisulfite, l-ascorbic acid, and ferrous salts are also used. Regarding the polymerization temperature during polymerization, a relatively low temperature is preferable because the molecular weight of the crosslinked polymer obtained becomes large, but in order to complete the polymerization, it is preferably within the range of 10°C or more and 80°C or less. When drying by heating the gel-like hydropolymer of the crosslinked polymer obtained by aqueous copolymerization based on the production method of the present invention, it is desirable to dry it as efficiently and in a short time as possible to prevent deterioration due to excessive heat. . As such a drying method, the gel-like hydrous polymer is divided into pieces by cutting or extrusion so that the surface area per unit volume is 9 cm 2 /cm 3 or more, and then it is dried with hot air at a temperature of 100 to 230°C. A method of drying by heating is particularly preferred. In the production method of the present invention, the acrylate monomer (A) and the crosslinkable monomer (B) are combined without using a surfactant.
If a surfactant is added at the gel-like hydropolymer stage after polymerizing a mixed aqueous solution with Copolymerization and crosslinking cannot be carried out. Furthermore, it is impossible for the surfactant to be uniformly distributed inside the gel-like hydrous polymer, and therefore it is impossible to prevent sticking during cutting or extrusion. moreover,
Even if the obtained crosslinked polymer is powdered, the surfactant is not uniformly distributed in such powder,
It cannot be expected to be effective in improving dust generation or preventing the formation of "mamako" when coming into contact with aqueous substances. The crosslinked polymer thus obtained based on the production method of the present invention is pulverized as necessary and used as a powder. There are no particular restrictions on the method of pulverization, and conventionally known methods can be used as appropriate. According to the present invention, even after heating and drying a gel-like hydrous polymer, surfactant fine particles or droplets are uniformly dispersed on the surface and inside of the dried product.
Can be easily crushed in a short time. In addition, even if fine powder is generated in this pulverization process, the fine powder tends to aggregate slightly due to the fine particles or fine droplets of the surfactant that are uniformly dispersed on the surface and inside the particle. Therefore, it has the advantage of not accumulating dust. When the crosslinked polymer thus obtained according to the production method of the present invention is used as an absorbent resin after being pulverized, it exhibits a high absorption capacity with particularly excellent initial absorption. This is because the crosslinked polymer based on the production method of the present invention is uniformly crosslinked by the crosslinkable monomer (B), and also because the surfactant has a relatively hydrophobic portion on the surface of the powder particles. The dispersion of the fine particles or droplets prevents the formation of a so-called "sticky" state when they come into contact with an aqueous substance, so that the aqueous substance penetrates each polymer particle in a short period of time.
This is thought to be due to the subsequent swelling. In addition, when used as a thickening resin, it has a great effect of preventing the formation of "sticks" when dispersed in a dispersion medium such as water, and has the advantage that uniform dispersion can be carried out in a short time. The crosslinked polymer obtained based on the production method of the present invention has excellent absorbency and thickening properties, does not become sticky when it comes into contact with the absorbed liquid, and has good retention properties after absorption, and is resistant to the human body. Within a safe range for skin
Can be adjusted to PH. Therefore, it is used in absorbent materials for disposable diapers and sanitary cotton, thickeners for poultices, thickeners for fragrance gels, emulsion stabilizers and thickeners for cosmetics and toiletries, carpet backing agents, and water-based paints. It can be used in a wide range of applications, including as a thickener, a spreading agent for agricultural chemicals, and as a soil conditioner for agriculture and horticulture by mixing with soil to increase water retention. The production method of the present invention allows crosslinked polymers with such excellent physical properties to be produced without using organic solvents, without the need for complicated processes such as saponification and washing, and without the need for cumbersome processes such as saponification and washing. The present invention provides a highly productive manufacturing method that eliminates adhesion during molding. Hereinafter, the manufacturing method of the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited by these Examples. In addition, % in Examples and Comparative Examples is weight % unless otherwise specified.
, and parts mean parts by weight. Example 1 The inner surface was lined with tetrafluoroethylene resin
Sodium acrylate 75
4000 g of an aqueous solution of acrylate monomer (A) consisting of mol% and acrylic acid 25 mol% (monomer concentration 43
%), various crosslinkable monomers (B) and surfactants in the amounts shown in Table 1, and the solution temperature was raised to 40% under a nitrogen atmosphere.
After the mixture was cooled to ℃, 0.6 g of ammonium persulfate and 0.2 g of sodium bisulfite were added and uniformly dissolved. Polymerization proceeded slowly and became a cloudy gel with the generation of heat. The temperature of the reaction system reached 55 to 80°C within 2 to 5 hours after the start of polymerization. After 7 hours from the start of polymerization, the sealed container was opened and the gel-like hydrous polymer produced was taken out. Both gel-like hydrous polymers were easily released from the polymerization container. Each of the gel-like hydrous polymers taken out was cut into 1 cm square pieces using a steel cutter, and there was no adhesion to the cutter during this cutting process, and the workability was good. Next, the cut 1 cm square gel-like hydropolymer was cut into 1.5 mm diameter pieces using a screw type extruder with a contact part made of SUS316, a screw diameter of 30 mm, L/D = 17, and a screw rotation speed of 45 rpm. It was extruded from a perforated nozzle to form a string-like gel with a diameter of about 2 mm. The surface area per unit volume of this string-like gel was about 20 cm 2 /cm 3 . This string-like gel was dried in a hot air dryer at 180° C. for 90 minutes to obtain alkali metal acrylate crosslinked polymers (crosslinked polymers (1) to (4)). Each of the obtained crosslinked polymers was made into powder using a vibrating pulverizer. 0.2 g of this powder was uniformly placed in a tea bag made of non-woven fabric (40 mm x 150 mm), immersed in 0.9% saline, and the weights were measured after 3 minutes and 5 minutes, respectively. Using the absorbed weight of only the tea bag as a blank, the swelling ratio of the crosslinked polymer was determined according to the following formula. Swelling ratio = Weight after absorption (g) - Blank (g) / Weight of powder (g) In addition, 20 g of the obtained powder was placed in a 100 ml glass sample bottle, and after shaking for a certain period of time, dust generation was examined. Ta. Next, the viscosity of a 1% aqueous dispersion of each crosslinked powder was measured using a B-type viscometer (25° C., 12 rpm).
The results are shown in Table 1. All of the crosslinked polymers obtained according to the method of the present invention exhibited excellent initial absorption properties, and the swollen gels were not sticky. In addition, there was almost no dust generation, and the viscosity of the aqueous dispersion of each crosslinked polymer was high, showing excellent thickening properties. Also,
The PH of 1% aqueous dispersion of these crosslinked polymers is 7.0, which is safer for human skin than the PH of 1% aqueous solution of commercially available high molecular weight sodium polyacrylate, which is 9.6. showed that. Comparative Example 1 A polymer (comparative polymer (1)) was obtained in the same manner as in Example 1, except that the crosslinkable monomer (B) was not used. This comparative polymer (1) contained a large amount of soluble matter even after being made into powder, making it unsuitable as an absorbent.As shown in Table 1, the viscosity was also low, making it unsuitable as a thickener. Comparative Example 2 A polymer (comparative polymer (2)) was obtained in the same manner as in Example 1 except that no surfactant was used. In this comparative polymer (2), the crosslinking monomer was not uniformly dissolved in the pre-polymerization stage, and it was highly sticky to the polymerization container in the post-polymerization stage, making it difficult to release from the mold. Furthermore, the dust generation property of the obtained powder was also high. Comparative Example 3 The proportion of sodium acrylate in the acrylate monomer (A) was 40 mol%, and the addition rate of pentaerythritol trimethacrylate as the crosslinkable monomer (B) was 0.1 part (based on 100 parts of monomer). ) and “Neoperex 05” manufactured by Kao Atlas Co., Ltd. as a surfactant.
Polymerization was attempted in the same manner as in Example 1 except that 1 part of (based on 100 parts of monomer) was used. However, polymerization did not start, so when the system temperature was raised to 60°C, rapid polymerization occurred. The obtained water-containing polymer was very soft and highly sticky, and had poor releasability from the polymerization container. In addition, the swelling ratio of the powder obtained in the same manner as in Example 1 in 0.9% saline solution was measured to 24% in 3 minutes.
It showed a small value of 26 times in 5 minutes.
【表】
実施例 ２
実施例１において得られた架橋重合体(3)の粉体
10部を湿布薬増粘剤として用い、グリセリン40
部、カオリン20部、ゼラチン10部、アルギン酸ソ
ーダ４部及び温水104部と共に混練して湿布薬基
材を調製した。この基剤の粘度（Ｂ型粘度、
2rpm）は4.0×106cps以上、PH（基剤を水で10倍
に希釈して測定）は7.1であつた。
比較のため、市販の高分子量ポリアクリル酸ソ
ーダを湿布薬増粘剤として用いる他は同組成で湿
布薬基材を調製したところ、この基材の粘度は
1.26×106cpsであり、PH（基材を水で10倍に希釈
して測定）は高く、9.1であつた。これにより、
本発明の方法に基づいて得られた架橋重合体はす
ぐれた増粘性と安全なPH値を示す事が明らかであ
る。
実施例 ３
実施例１において得られた架橋重合体(2)の粉体
を用いて生理綿を作成し、吸収能を測定した。
吸収紙（６cm×16cm）２枚の間に架橋重合体(2)
の粉体0.5ｇを均一に分散し、エンボスロールで
プレスして吸収シートを得た。得られた吸収シー
トを市販生理綿（ミニタイプ）の吸収紙と置きか
え、全重量6.0ｇの生理綿を作成した。この生理
綿の使用面を上にして重量既知の10メツシユ金網
上にのせ、水道水を５分間注水し、次いで１分間
傾斜したのち重量を測定したところ108.0ｇであ
つた。比較のため、市販生理綿（重量6.0ｇ）に
ついても同様に測定したところ、吸水後の重量は
55.6ｇであつた。[Table] Example 2 Powder of crosslinked polymer (3) obtained in Example 1
10 parts glycerin 40 parts used as a poultice thickener
1 part, 20 parts of kaolin, 10 parts of gelatin, 4 parts of sodium alginate, and 104 parts of warm water to prepare a poultice base. The viscosity of this base (B type viscosity,
2 rpm) was 4.0×10 6 cps or more, and the pH (measured by diluting the base 10 times with water) was 7.1. For comparison, a poultice base material was prepared with the same composition except that commercially available high molecular weight sodium polyacrylate was used as the poultice thickener, and the viscosity of this base material was
It was 1.26×10 6 cps, and the pH (measured by diluting the base material 10 times with water) was high, at 9.1. This results in
It is clear that the crosslinked polymer obtained according to the method of the present invention exhibits excellent thickening properties and safe pH values. Example 3 Physiological cotton was prepared using the powder of the crosslinked polymer (2) obtained in Example 1, and its absorption capacity was measured. Cross-linked polymer (2) between two sheets of absorbent paper (6cm x 16cm)
0.5 g of the powder was uniformly dispersed and pressed with an embossing roll to obtain an absorbent sheet. The obtained absorbent sheet was replaced with commercially available sanitary cotton (mini type) absorbent paper to prepare sanitary cotton having a total weight of 6.0 g. This sanitary cotton was placed on a 10-mesh wire mesh of known weight with the use side facing up, tap water was poured for 5 minutes, the cotton was tilted for 1 minute, and the weight was measured, and the weight was 108.0 g. For comparison, commercially available sanitary cotton (weight 6.0g) was measured in the same way, and the weight after water absorption was
It weighed 55.6g.
Claims (1)
下、アクリル酸０〜50モル％とアクリル酸アルカ
リ金属塩50〜100モル％とからなるアクリル酸塩
系単量体(A)100重量部と架橋性単量体(B)0.001〜５
重量部との混合物を25重量％以上の濃度で水溶液
共重合することを特徴とするアクリル酸アルカリ
金属塩架橋重合体の製造方法。 ２ 界面活性剤の使用量がアクリル酸塩系単量体
(A)100重量部に対して0.01〜10重量部の範囲の比
率の量である特許請求の範囲第１項記載の製造方
法。 ３ 界面活性剤が水溶性及び又は水分散性界面活
性剤でHLBが７以上の非イオン系界面活性剤で
ある特許請求の範囲第１項記載の製造方法。 ４ アルカリ金属がナトリウムである特許請求の
範囲第１項記載の製造方法。 ５ 水溶性及び／又は水分散性界面活性剤の存在
下、アクリル酸０〜50モル％とアクリル酸アルカ
リ金属塩50〜100モル％とからなるアクリル酸塩
系単量体(A)100重量部と架橋性単量体(B)0.001〜５
重量部との混合物を25重量％以上の濃度で水溶液
共重合して得られたゲル状含水重合体を加熱乾燥
することを特徴とするアクリル酸アルカリ金属塩
架橋重合体の製造方法。 ６ 界面活性剤の使用量がアクリル酸塩系単量体
(A)100重量部に対して0.01〜10重量部の範囲の比
率の量である特許請求の範囲第５項記載の製造方
法。 ７ 界面活性剤が水溶性及び／又は水分散性界面
活性剤でHLBが７以上の非イオン系界面活性剤
である特許請求の範囲第５項記載の製造方法。 ８ アルカリ金属がナトリウムである特許請求の
範囲第５項記載の製造方法。 ９ ゲル状含水重合体を単位体積当りの表面積が
９cm2/cm3以上になるように細分化したのち100〜
230℃の温度の熱風で加熱乾燥する特許請求の範
囲第５項記載の製造方法。[Claims] 1. An acrylate monomer consisting of 0 to 50 mol% of acrylic acid and 50 to 100 mol% of an alkali metal salt of acrylic acid in the presence of a water-soluble and/or water-dispersible surfactant. (A) 100 parts by weight and crosslinkable monomer (B) 0.001-5
1. A method for producing an alkali metal acrylic salt crosslinked polymer, which comprises copolymerizing a mixture with parts by weight in an aqueous solution at a concentration of 25% by weight or more. 2 The amount of surfactant used is acrylate monomer
The manufacturing method according to claim 1, wherein (A) is in an amount ranging from 0.01 to 10 parts by weight per 100 parts by weight. 3. The manufacturing method according to claim 1, wherein the surfactant is a water-soluble and/or water-dispersible surfactant and a nonionic surfactant with an HLB of 7 or more. 4. The manufacturing method according to claim 1, wherein the alkali metal is sodium. 5 100 parts by weight of an acrylate monomer (A) consisting of 0 to 50 mol% of acrylic acid and 50 to 100 mol% of an alkali metal acrylate in the presence of a water-soluble and/or water-dispersible surfactant. and crosslinkable monomer (B) 0.001-5
1. A method for producing an alkali metal acrylic salt crosslinked polymer, which comprises heating and drying a gel-like hydrous polymer obtained by copolymerizing a mixture with parts by weight in an aqueous solution at a concentration of 25% by weight or more. 6 The amount of surfactant used is acrylate monomer
6. The method according to claim 5, wherein (A) is in an amount ranging from 0.01 to 10 parts by weight relative to 100 parts by weight. 7. The manufacturing method according to claim 5, wherein the surfactant is a water-soluble and/or water-dispersible surfactant and a nonionic surfactant with an HLB of 7 or more. 8. The manufacturing method according to claim 5, wherein the alkali metal is sodium. 9 After dividing the gel-like hydrous polymer into smaller pieces so that the surface area per unit volume is 9 cm 2 /cm 3 or more,
The manufacturing method according to claim 5, which comprises heating and drying with hot air at a temperature of 230°C.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4112579A JPS55133413A (en) | 1979-04-06 | 1979-04-06 | Preparation of crosslinked alkali metal acrylate polymer |
| US06/137,640 US4286082A (en) | 1979-04-06 | 1980-04-07 | Absorbent resin composition and process for producing same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4112579A JPS55133413A (en) | 1979-04-06 | 1979-04-06 | Preparation of crosslinked alkali metal acrylate polymer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS55133413A JPS55133413A (en) | 1980-10-17 |
| JPS6136763B2 true JPS6136763B2 (en) | 1986-08-20 |
Family
ID=12599722
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4112579A Granted JPS55133413A (en) | 1979-04-06 | 1979-04-06 | Preparation of crosslinked alkali metal acrylate polymer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55133413A (en) |
Cited By (1)
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|---|---|---|---|---|
| JP2003527213A (en) * | 2000-03-21 | 2003-09-16 | キンバリー クラーク ワールドワイド インコーポレイテッド | Super absorbent material with permanent wettability |
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| US5610208A (en) | 1994-02-17 | 1997-03-11 | Nippon Shokubai Co., Ltd. | Water-absorbent agent, method for production thereof, and water-absorbent composition |
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-
1979
- 1979-04-06 JP JP4112579A patent/JPS55133413A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003527213A (en) * | 2000-03-21 | 2003-09-16 | キンバリー クラーク ワールドワイド インコーポレイテッド | Super absorbent material with permanent wettability |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS55133413A (en) | 1980-10-17 |
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