发明名称 |
RETENTION AGENT |
摘要 |
A method and an agent for improving the retention when dewatering a cellulosic fibre suspension are disclosed. In the method, there is added to the suspension a retention agent containing a phenol-formaldehyde resin and a polyethylene oxide, and the method is characterised in that a modified phenol-formaldehyde resin containing cationic groups is added to the suspension. The modified phenol-formaldehyde resin preferably has a cationicity of about 5-85 % and the cationic groups preferably consist of amine groups. The polyethylene oxide in the retention agent preferably has a molecular weight of about 0.5-20 x 10<6>. The modified phenol-formaldehyde resin and the polyethylene oxide are preferably added to the suspension in a weight ratio of modified phenol-formaldhyde resin:polyethylene oxide of from 1:5 to 50:1, and the amount of polyethylene oxide added preferably is about 10-1000 ppm, based on the dry solids content of the suspension. Preferably first the modified phenol-formaldehyle resin is added to the suspension and then the polyethylene oxide.
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申请公布号 |
WO9902775(A1) |
申请公布日期 |
1999.01.21 |
申请号 |
WO1998SE01233 |
申请日期 |
1998.06.25 |
申请人 |
KEMIRA KEMI AB;ROSENGREN, BO;GYTEL, ULLA |
发明人 |
ROSENGREN, BO;GYTEL, ULLA |
分类号 |
D21H17/48;D21H17/53;D21H21/10;(IPC1-7):D21H17/48 |
主分类号 |
D21H17/48 |
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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