Claims
- 1. A process for sizing paper which comprises adding to an aqueous suspension containing cellulosic fibres, and optional fillers, and(i) a sizing dispersion comprising a sizing agent and at least one polymer having one or more aromatic groups, and (ii) a sizing promoter comprising at least one polymer having one or more aromatic groups, forming and draining the obtained suspension, wherein the sizing dispersion and the sizing promoter are added separately to the aqueous suspension.
- 2. The process according to claim 1, wherein the sizing dispersion is anionic or cationic.
- 3. The process according to claim 1, wherein the sizing agent is a cellulose-reactive sizing agent.
- 4. The process according to claim 3, wherein the cellulose-reactive sizing agent is a ketene dimer or an acid anhydride.
- 5. The process according to claim 3, wherein the sizing agent is a ketene dimer.
- 6. The process according to claim 1, wherein the polymer having one or more aromatic groups comprised in the sizing promoter is charged.
- 7. The process according to claim 1, wherein the polymer having one or more aromatic groups comprised in the sizing dispersion is anionic or cationic.
- 8. A process for sizing paper which comprises adding to an aqueous suspension containing cellulosic fibres, and optional fillers, and(i) a sizing dispersion comprising a cellulose-reactive sizing agent and an anionic polymer having one or more aromatic groups being a step-growth polymer, a polysaccharide or a naturally occurring aromatic polymer, and (ii) a sizing promoter comprising at least one cationic organic polymer having one or more aromatic groups, forming and draining the obtained suspension, wherein the sizing dispersion and the sizing promoter are added separately to the aqueous suspension.
- 9. The process according to claim 8, wherein the cellulose-reactive sizing agent is a ketene dimer or an acid anhydride.
- 10. The process according to claim 8, wherein the cellulose-reactive sizing agent is a ketene dimer.
- 11. The process according to claim 8, wherein the cationic organic polymer of the sizing promoter is a cationic polysaccharide or a cationic vinyl addition polymer.
- 12. The process according to claim 8, wherein the cationic organic polymer of the promoter is a cationic polysaccharide.
- 13. The process according to claim 11, wherein the cationic organic polymer is a cationic polysaccharide having the structural formula (I): wherein P is a residue of a polysaccharide; A is a chain of atoms comprising C and H atoms attaching N to the polysaccharide residue, R1 and R2 are each H or a hydrocarbon group, R3 is an aromatic hydrocarbon group, n is an integer from 2 up to 300000, and X− is an anionic counter ion; or vinyl addition polymers obtained by polymerising a cationic monomer or a monomer mixture comprising a cationic monomer represented by the general formula (II): wherein R1 is H or CH3; R2 and R3 are each an alkyl group having from 1 to 3 carbon atoms, A1 is O or NH, B1 is an alkylene group having from 2 to 8 carbon atoms or a hydroxy propylene group, Q is a substituent containing an aromatic group, and X− is an anionic counterion.
- 14. The process according to claim 12, wherein the cationic organic polymer is a cationic polysaccharide having the structural formula (I): wherein P is a residue of a polysaccharide; A is a chain of atoms comprising C and H atoms attaching N to the polysaccharide residue, R1 and R2 are each H or a hydrocarbon group, R3 is an aromatic hydrocarbon group, n is an integer from 2 up to 300000, and X− is an anionic counter ion.
- 15. The process according to claim 14, wherein A is an alkylene group with from 2 to 18 carbon atoms, optionally interrupted or substituted by one or more heteroatoms; R1 and R2 are each H or an alkyl group having from 1 to 3 carbon atoms; R3 is a bezyl or phenylethyl group.
- 16. The process according to claim 8, wherein the sizing promoter further comprises anionic microparticulate particles.
- 17. The process according to claim 16, wherein the anionic microparticulate particles are silica-based particles.
- 18. The process according to claim 16, wherein the anionic microparticulate particles comprised in the sizing promoter are added to the aqueous suspension after both the sizing dispersion and the cationic organic polymer comprised in the sizing promoter.
- 19. The process according to claim 8, wherein the conductivity of the suspension is at least 3.5 mS/cm.
- 20. The process according to claim 8, wherein the conductivity of the suspension is at least 4.5 mS/cm.
Priority Claims (4)
Number |
Date |
Country |
Kind |
00850135 |
Aug 2000 |
EP |
|
00850136 |
Aug 2000 |
EP |
|
00850137 |
Aug 2000 |
EP |
|
00850195 |
Nov 2000 |
EP |
|
Parent Case Info
This application claims the benefit of provisional applications Nos. 60/223/367, 60/223,368, 60/223,369, all filed Aug. 7, 2000, and 60/249/365, filed Nov. 16, 2000.
US Referenced Citations (15)
Foreign Referenced Citations (16)
Number |
Date |
Country |
0 056 876 |
Aug 1982 |
EP |
0 189 935 A 2 |
Aug 1986 |
EP |
0 525 751 |
Feb 1993 |
EP |
0 805 234 |
Nov 1997 |
EP |
0 984 101 |
Mar 2000 |
EP |
WO 9424169 |
Oct 1994 |
WO |
WO 9521296 |
Aug 1995 |
WO |
WO 9833979 |
Aug 1998 |
WO |
WO 9833980 |
Aug 1998 |
WO |
WO 9833982 |
Aug 1998 |
WO |
WO 9955962 |
Nov 1999 |
WO |
WO 9955964 |
Nov 1999 |
WO |
WO 9955965 |
Nov 1999 |
WO |
WO 0006490 |
Feb 2000 |
WO |
WO 0023651 |
Apr 2000 |
WO |
WO 0049227 |
Aug 2000 |
WO |
Non-Patent Literature Citations (2)
Entry |
Laid-Open Patent Gazette; Laid-open No. 1992-363301; Dec. 16, 1992. |
Starch/Starke 41 (1989) No. 5 S. 192-196 Synthesis and Characterization of Quaternary Ammonium Compounds of Guar Gum and Hydroxyethyl Guar Gum; S.P. Patel; et al. |
Provisional Applications (4)
|
Number |
Date |
Country |
|
60/249365 |
Nov 2000 |
US |
|
60/223367 |
Aug 2000 |
US |
|
60/223368 |
Aug 2000 |
US |
|
60/223369 |
Aug 2000 |
US |