| (19) |
 |
|
(11) |
EP 0 831 177 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
05.01.2000 Bulletin 2000/01 |
| (43) |
Date of publication A2: |
|
25.03.1998 Bulletin 1998/13 |
| (22) |
Date of filing: 23.09.1997 |
|
|
| (84) |
Designated Contracting States: |
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AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
| (30) |
Priority: |
24.09.1996 US 719283
|
| (71) |
Applicant: NALCO CHEMICAL COMPANY |
|
Naperville Illinois 60563-1198 (US) |
|
| (72) |
Inventors: |
|
- Wong Shing, Jane B.
Aurora, Illinois 60504 (US)
- Hurlock, John R.
Hickory Hills, Illinois 60457 (US)
|
| (74) |
Representative: Wibbelmann, Jobst, Dr., Dipl.-Chem. |
|
Wuesthoff & Wuesthoff, Patent- und Rechtsanwälte, Schweigerstrasse 2
81541 München
81541 München (DE) |
|
| |
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| (54) |
Hydrophilic dispersion polymers for paper applications |
(57) A papermaking process comprising forming an aqueous cellulosic papermaking slurry
and adding a hydrophilic dispersion polymer to the slurry to increase retention and/or
drainage is disclosed. The hydrophilic dispersion polymer comprises (a) a cationic
monomer and (b) a second monomer represented by (meth)acrylamide (in an aqueous solution
of a polyvalent anionic salt), wherein the polymerization is carried out in the presence
of either an organic high-molecular weight multivalent cation comprising a water-soluble
polymer containing at least one (a) monomer and/or poly diallyl dimethyl ammonium
chloride (DADMAC). After addition of the polymers, the slurry is drained to form a
sheet, and the sheet is dried.