发明名称 |
Process for the continuous preparation of water-absorbent polymers |
摘要 |
<p>The invention relates generally to a process for the preparation of water-absorbent polymer particles, comprising the process steps of
(i) preparing an aqueous monomer solution comprising at least partially neutralized, monoethylenically unsaturated monomers bearing carboxylic acid groups (±1) and at least one crosslinker (±3);
(ii) optionally adding fine particles of a water-absorbent polymer or aqueous salt solutions to the aqueous monomer solution;
(iii) adding a polymerization initiator or a at least one component of a polymerization initiator system that comprises two or more components to the aqueous monomer solution;
(iv) decreasing the oxygen content of the aqueous monomer solution;
(v) charging the aqueous monomer solution into a polymerization reactor;
(vi) polymerizing the monomers in the aqueous monomer solution in the polymerization reactor;
(vii) discharging the polymer gel strand out of the polymerization reactor and optionally comminuting the polymer gel thereby obtaining polymer gel particles;
(viii) drying the polymer gel particles;
(ix) grinding the dried polymer gel particles thereby obtaining particulate water-absorbent polymer particles;
(x) sizing the grinded water-absorbent polymer particles; and
(xi) crosslinking the surface of the grinded and sized water-absorbent polymer particles;
wherein process step (xi) comprises the steps of:
(x1a) mixing the particles with an aqueous crosslinker solution; and
(x2a) heat-treating the mixture obtained in process step (x1a) in a horizontally operated mixing device,
wherein the horizontally operated mixing device is hydraulically driven.</p> |
申请公布号 |
EP2614841(A1) |
申请公布日期 |
2013.07.17 |
申请号 |
EP20120150881 |
申请日期 |
2012.01.12 |
申请人 |
EVONIK INDUSTRIES AG |
发明人 |
PLOECHINGER, HARALD;FRICKER, DANIEL;WALTER, RICHARD;HAGER, MARC |
分类号 |
A61L15/22;A61L15/60;B01J3/00;B01J19/20;B01J19/22;B28C5/00;C08F6/00;C08J3/24;C08L33/02 |
主分类号 |
A61L15/22 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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