Patent US4772359A successfully refreshed from Google Patents.
US4772359A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of paper, board and cardboard
Assignee: BASF SE
•
Filing: 1987-05-29
•
Granted: 1988-09-20
•
Expires: 2007-05-29
Abstract
Abstract Paper, board and cardboard are produced by draining a pulp slurry in the presence of high molecular weight, water-soluble polymers of N-vinylamides as drainage aids, retention agents and flocculants. These polymers are particularly effective in a pulp slurry which has a high content of interfering substances and other phenolic compounds.
Inventors
- 👤 Friedrich Linhart
- 👤 Hans-Juergen Degen
- 👤 Werner Auhorn
- 👤 Michael Kroener
- 👤 Heinrich Hartmann
- 👤 Wilfried Heide
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:00
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/37
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
99 words
In a papermaking process utilizing an aqueous pulp slurry, the improvement which increases the drainage rate and the retention of fines, fillers and pigments, which improvement comprises: adding to the pulp slurry an effective amount of a high molecular weight water-soluble polymer of N-substituted vinylamides having a K value of at least 130 (measured according to H. Fikentscher in 5% strength by weight sodium chloride solution at 25° C. and a polymer concentration of 0.1% by weight) and from 0.02 to 1.0% by weight, based on dry pulp, of a synthetic phenol resin or phenol-containing natural oligomers and/or polymers.
Claim 2
Dependent Claim
99 words
In a papermaking process utilizing an aqueous pulp slurry, the improvement which increases the drainage rate and the retention of fines, fillers and pigments, which improvement comprises: adding to the pulp slurry an effective amount of a high molecular weight water-soluble polymer of N-substituted vinylamides having a K value of at least 130 (measured according to H. Fikentscher in 5% strength by weight sodium chloride solution at 25° C. and a polymer concentration of 0.1% by weight) and from 0.02 to 1.0% by weight, based on dry pulp, of a synthetic phenol resin or phenol-containing natural oligomers and/or polymers.
Claim 3
Dependent Claim
36 words
A process as claimed in claim 1 wherein the polymer is of an open-chain amide of the formula ##STR3## where R 1 and R 2 are each H, CH 3 or C 2 H 5 .
Claim 4
Dependent Claim
54 words
A process as claimed in claim 1 wherein the polymer is of a cyclic N-vinylamide of the formula ##STR4## where X is --CH 2 --, --CH 2 --CH 2 --, --CH 2 --CH 2 --CH 2 --, --O-- or --O--CH 2 -- and R 3 is H, C 1 -C 3 -alkyl or phenyl,.
Claim 5
Dependent Claim
70 words
A process as claimed in claim 1, wherein homopolymers or copolymers of N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylformamide, N-methyl-N-vinylacetamide, N-ethyl-N-vinylformamide, N-ethyl-N-vinylacetamide and N-vinylpropionamide are used as drainage aids, retention agents and flocculants, the polymers being free of aminoalkyl groups and having a K value of not less than 130 (measured according to H. Fikentscher in 5% strength by weight sodium chloride solution at 25° C. and a polymer concentration of 0.1% by weight).
Claim 6
Dependent Claim
72 words
A process as claimed in claim 1, wherein homopolymers or copolymers of N-vinylpyrrolidone, N-vinylpiperidone, N-vinylcaprolactam, N-vinyl-3-methylpyrrolidone, N-vinyl-5-methylpyrrolidone, N-vinyl-5-phenylpyrrolidone, N-vinyl-3-benzylpyrrolidone, N-vinyl-4-methylpiperidone, N-vinyl-2-oxazolidone, N-vinyl-5-methyl-2-oxazolidone, N-vinyl-5-ethyl-2-oxazolidone, N-vinyl-5-phenyl-2-oxazolidone, N-vinyl-4-methyl-2-oxazolidone, N-vinyl-3-oxazolid-2-one and N-vinylmorpholinone are used as drainage aids, retention agents and flocculants, the K value of the polymers being not less than 130 (measured according to H. Fikentscher in 5% strength by weight sodium chloride solution at 25° C. and a polymer concentration of 0.1% by weight).
Claim 7
Dependent Claim
19 words
A process as claimed in claim 1, wherein the copolymer is of an open-chain or cyclic N-vinylamide is used.
Claim 8
Dependent Claim
22 words
A process as claimed in claim 1, wherein the copolymer is of N-vinylformamide and N-vinylpyrrolidone or of N-vinylformamide and N-vinylcaprolactam is used.
Claim 9
Dependent Claim
22 words
A process as claimed in claim 1, wherein a resol-type or novolak-type condensate of phenol and formaldehyde is the synthetic phenol resin.
Claim 10
Dependent Claim
23 words
A process as claimed in claim 1, wherein compounds of the lignin or humic acid type is the phenol-containing natural oligomers and/or polymers.
Claim 11
Dependent Claim
18 words
A process as claimed in claim 1, wherein a wood extract is the phenol-containing natural oligomers and/or polymers.
Claim 12
Dependent Claim
20 words
A process as claimed in claim 1, wherein unbleached sulfate pulp, semi-chemical pulp and/or mechanical pulp are the pulp slurry.
Claim 13
Dependent Claim
13 words
A process as claimed in claim 2, wherein the polymer is poly-N-vinyl formamide.
Claim 14
Dependent Claim
44 words
A process as claimed in claim 12, wherein the poly-N-vinyl formamide has a K value of not less than 130 (measured according to H. Fikentscher in 5% strength by weight sodium chloride solution at 25° C. and a polymer concentration of 0.1% by weight).
Claim 15
Dependent Claim
17 words
A process as claimed in claim 13, wherein the poly-N-vinyl formamide has a K value of 175.
Claim 16
Dependent Claim
17 words
A process as claimed in claim 13, wherein the poly-N-vinyl formamide has a K value of 190.
Claim 17
Dependent Claim
17 words
A process as claimed in claim 13, wherein the poly-N-vinyl formamide has a K value of 227.
References Cited (Backward Citations)
GB848936A
Cited
GB937935A
Cited
US3036950A
Cited
US3081219A
Cited
GB994499A
Cited
GB1141166A
Cited
US3597314A
Cited
US4057533A
Cited
US3926718A
Cited
US4144123A
Cited
US4167439A
Cited
US4305781A
Cited
US4444662A
Cited
US4421602A
Cited
US4444667A
Cited
US4644020A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-09-20 | 1992-03-21 | 1992-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-20 | 1996-03-21 | 1996-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-20 | 2000-03-21 | 2000-09-20 | $7700.00 | Window Closed / Lapsed |