US4925530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loaded paper
Assignee: Wiggins Teape Group Ltd
•
Filing: 1988-07-20
•
Granted: 1990-05-15
•
Expires: 2008-07-20
Abstract
Abstract Aqueous suspensions of papermaking fibres and filler are each separately treated with an anionic or a cationic polymer, after which the filler (preferably) or the papermaking fibre is treated with a polymer of opposite charge to that used in the initial treatment. The filler and papermaking suspensions are then mixed to form a papermaking stock, with dilution as necessary before, during or after the mixing operation. This stock is then used to form a loaded paper web in conventional manner. The initial treating polymer is preferably a papermaking retention aid or flocculant, e.g. a cationic polyarcylamide or an amine/amide/epichlorohydrin copolymer in the case of cationic materials or an anionic polyacrylamide in the case of anionic materials. The further treating polymer is preferably an anionic or cationic starch, depending on the charge of the initial treating polymer.
Inventors
- 👤 Peter Sinclair
- 👤 Angela J. Hayes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:31
CPC Classifications
D; D21; D21H; D21H23/00; D21H23/02; D21H23/04; D21H23/06; D21H23/14; D21H17/00; D21H17/20; D21H17/33; D21H17/34; D21H17/37; D21H17/375; D21H17/41; D21H17/42; D21H17/43; D21H17/44; D21H17/45; D21H17/455; D21H17/46; D21H17/54; D21H17/55
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
182 words
A process for the production of loaded paper from papermaking fibre and filler, comprising the steps of: (a) treating the papermaking fibre in an aqueous medium with a charged synthetic polymer; (b) separately treating the filler in an aqueous medium with a charged synthetic polymer, with the proviso that if the charged synthetic polymer used to treat the filler is anionic it is selected from papermaking flocculents and retention aids; (c) selecting the charged synthetic polymer used in step (a) and the charged synthetic polymer used in step (b) such that both have the same charge polarity; (d) additionally treating the filler with a charged polymer of opposite charge polarity from that of the polymer(s) used in steps (a) and (b); (e) mixing aqueous suspensions of treated filler and treated papermaking fibre from steps (a), (b) and (d) to form a papermaking stock, diluting as necessary before, during or after the mixing operation; and (f) draining the papermaking stock to form a loaded paper web, wherein the filler, papermaking fibre and charged polymers are used in amounts effective to produce loaded paper.
Claim 2
Dependent Claim
182 words
A process for the production of loaded paper from papermaking fibre and filler, comprising the steps of: (a) treating the papermaking fibre in an aqueous medium with a charged synthetic polymer; (b) separately treating the filler in an aqueous medium with a charged synthetic polymer, with the proviso that if the charged synthetic polymer used to treat the filler is anionic it is selected from papermaking flocculents and retention aids; (c) selecting the charged synthetic polymer used in step (a) and the charged synthetic polymer used in step (b) such that both have the same charge polarity; (d) additionally treating the filler with a charged polymer of opposite charge polarity from that of the polymer(s) used in steps (a) and (b); (e) mixing aqueous suspensions of treated filler and treated papermaking fibre from steps (a), (b) and (d) to form a papermaking stock, diluting as necessary before, during or after the mixing operation; and (f) draining the papermaking stock to form a loaded paper web, wherein the filler, papermaking fibre and charged polymers are used in amounts effective to produce loaded paper.
Claim 3
Dependent Claim
24 words
A process as claimed in claim 1, wherein the polymer used in the step (a) treatment is a cationic papermaking retention aid or flocculant.
Claim 4
Dependent Claim
25 words
A process as claimed in claim 2 wherein the polymer used in the step (a) treatment is a cationic polyacrylamide or a cationic amine/amide/epichlorohydrin copolymer.
Claim 5
Dependent Claim
36 words
A process as claimed in claim 3, wherein the polymer used in the step (a) treatment is used in an amount of at least 0.15% by weight, based on the dry weight of the papermaking fibre.
Claim 6
Dependent Claim
37 words
A process as claimed in claim 4, wherein the polymer used in the step (a) treatment is used in an amount of from 0.2 to 0.4% by weight, based on the dry weight of the papermaking fibre.
Claim 7
Dependent Claim
24 words
A process as claimed in claim 1, wherein the polymer used in the step (b) treatment is a cationic papermaking retention aid or flocculant.
Claim 8
Dependent Claim
25 words
A process as claimed in claim 6, wherein the polymer used in the step (b) treatment is a cationic polyacrylamide or a cationic amine/amide/epichlorohydrin copolymer.
Claim 9
Dependent Claim
38 words
A process as claimed in claim 6 or claim 7, wherein the polymer used in the step (b) treatment is used in an amount of at least 0.1% by weight, based on the dry weight of the filler.
Claim 10
Dependent Claim
36 words
A process as claimed in claim 8, wherein the polymer used in the step (b) treatment is used in an amount of from 0.2 to 1.0% by weight, based on the dry weight of the filler.
Claim 11
Dependent Claim
36 words
A process as claimed in claim 9, wherein the polymer used in the step (b) treatment is used in an amount of from 0.3 to 1.0% by weight, based on the dry weight of the filler.
Claim 12
Dependent Claim
20 words
A process as claimed in claim 2, wherein the polymer used in the step (c) treatment is an anionic starch.
Claim 13
Dependent Claim
30 words
A process as claimed in claim 11, wherein the anionic starch is used in an amount of at least 4% by weight, based on the dry weight of the filler.
Claim 14
Dependent Claim
31 words
A process as claimed in claim 12, wherein the anionic starch is used in an amount of from 5 to 10% by weight, based on the dry weight of the filler.
Claim 15
Dependent Claim
31 words
A process as claimed in claim 11, wherein the weight ratio on a dry basis of the amounts of polymer used in steps (b) and (c) is from 1:6 to 1:40.
Claim 16
Dependent Claim
16 words
A process as claimed in claim 14, wherein said weight ratio is from 1:6 to 1:14.
Claim 17
Dependent Claim
24 words
A process as claimed in claim 1, wherein the polymer used in the step (a) treatment is an anionic papermaking retention aid or flocculant.
Claim 18
Dependent Claim
20 words
A process as claimed in claim 16, wherein the polymer used in the step (a) treatment is an anionic polyacrylamide.
Claim 19
Dependent Claim
39 words
A process as claimed in claim 16 or claim 17, wherein the polymer used in the step (a) treatment is used in an amount of at least 0.15% by weight, based on the dry weight of the papermaking fibre.
Claim 20
Dependent Claim
37 words
A process as claimed in claim 18 wherein the polymer used in the step (a) treatment is used in an amount of from 0.2 to 0.4% by weight, based on the dry weight of the papermaking fibre.
Claim 21
Dependent Claim
22 words
A process as claimed in claim 1, wherein the polymer used in step (b) is an anionic papermaking retention aid or flocculant.
Claim 22
Dependent Claim
18 words
A process as claimed in claim 20, wherein the polymer used in step (b) is an anionic polyacrylamide.
Claim 23
Dependent Claim
37 words
A process as claimed in claim 20 or 21, wherein the polymer used in the step (b) treatment is used in an amount of at least 0.1% by weight, based on the dry weight of the filler.
Claim 24
Dependent Claim
36 words
A process as claimed in claim 22, wherein the polymer used in the step (b) treatment is used in an amount of from 0.2 to 1.0% by weight, based on the dry weight of the filler.
Claim 25
Dependent Claim
20 words
A process as claimed in claim 16, wherein the polymer used in the step (c) treatment is a cationic starch.
Claim 26
Dependent Claim
30 words
A process as claimed in claim 24, wherein the cationic starch is used in an amount of at least 4% by weight, based on the dry weight of the filler.
Claim 27
Dependent Claim
30 words
A process as claimed in claim 25, wherein the cationic starch is used in an amount of 8 to 10% by weight, based on the dry weight of the filler.
Claim 28
Dependent Claim
31 words
A process as claimed in claim 24, wherein the weight ratio on a dry basis of the amounts of polymer used in steps (b) and (c) is from 1:12 to 1:100.
Claim 29
Dependent Claim
16 words
A process as claimed in claim 27, wherein said weight ratio is from 1:24 to 1:40.
Claim 30
Dependent Claim
118 words
A process for the production of loaded paper from paper making fibre and filler, comprising the steps of: (a) treating the papermaking fibre in an aqueous medium with a cationic synthetic polymer; (b) separately treating the filler in an aqueous medium with a cationic synthetic polymer; (c) treating the thus-treated filler with an anionic polymer; (d) mixing aqueous suspensions of treated papermaking fibre from step (a) and treated filler from steps (b) and (c) to form a papermaking stock, diluting as necessary before, during or after the papermaking operation; and (e) draining the papermaking stock to form a loaded paper web, wherein the filler, papermaking fibre and charged polymers are used in amounts effective to produce loaded paper.
Claim 31
Dependent Claim
118 words
A process for the production of loaded paper from paper making fibre and filler, comprising the steps of: (a) treating the papermaking fibre in an aqueous medium with a cationic synthetic polymer; (b) separately treating the filler in an aqueous medium with a cationic synthetic polymer; (c) treating the thus-treated filler with an anionic polymer; (d) mixing aqueous suspensions of treated papermaking fibre from step (a) and treated filler from steps (b) and (c) to form a papermaking stock, diluting as necessary before, during or after the papermaking operation; and (e) draining the papermaking stock to form a loaded paper web, wherein the filler, papermaking fibre and charged polymers are used in amounts effective to produce loaded paper.
Claim 32
Dependent Claim
36 words
A process as claimed in claim 29, wherein the polymer used in both steps (a) and (b) is a cationic papermaking retention aid or flocculant and the polymer used in step (c) is an anionic starch.
Claim 33
Dependent Claim
26 words
A process as claimed in claim 30 wherein the polymer used in both steps (a) and (b) is a cationic polyacrylamide or a cationic amine/amide/epichlorohydrin copolymer.
Claim 34
Dependent Claim
65 words
A process as claimed in claim 31, wherein the polymer used in the step (a) and (b) treatments is used in an amount of from 0.2 to 1.0% by weight, based on the dry weight of the papermaking fibre or filler, and the anionic starch is used in an amount of from 5 to 10% by weight, based on the dry weight of the filler.
Claim 35
Dependent Claim
128 words
A process for the production of loaded paper from papermaking fibre and filler, comprising the steps of: (a) treating the papermaking fibre in an aqueous medium with an anionic synthetic polymer; (b) separately treating the filler in an aqueous medium with an anionic synthetic polymer wherein the polymer is selected from papermaking flocculents and retention aids; (c) treating the thus-treated filler with a cationic polymer; (d) mixing aqueous suspensions of treated papermaking fibre from step (a) and treated filler from steps (b) and (c) to form a papermaking stock, diluting as necessary before, during or after the papermaking operation; and (e) draining the papermaking stock to form a loaded paper web, wherein the filler, papermaking fibre and charged polymers are used in amounts effective to produce loaded paper.
Claim 36
Dependent Claim
128 words
A process for the production of loaded paper from papermaking fibre and filler, comprising the steps of: (a) treating the papermaking fibre in an aqueous medium with an anionic synthetic polymer; (b) separately treating the filler in an aqueous medium with an anionic synthetic polymer wherein the polymer is selected from papermaking flocculents and retention aids; (c) treating the thus-treated filler with a cationic polymer; (d) mixing aqueous suspensions of treated papermaking fibre from step (a) and treated filler from steps (b) and (c) to form a papermaking stock, diluting as necessary before, during or after the papermaking operation; and (e) draining the papermaking stock to form a loaded paper web, wherein the filler, papermaking fibre and charged polymers are used in amounts effective to produce loaded paper.
Claim 37
Dependent Claim
36 words
A process as claimed in claim 33, wherein the polymer used in both steps (a) and (b) is an anionic papermaking retention aid or flocculant and the polymer used in step (c) is a cationic starch.
Claim 38
Dependent Claim
21 words
A process as claimed in claim 34 wherein the polymer used in both steps (a) and (b) is an anionic polyacrylamide.
Claim 39
Dependent Claim
65 words
A process as claimed in claim 35, wherein the polymer used in the step (a) and (b) treatments is used in an amount of from 0.2 to 0.4% by weight, based on the dry weight of the papermaking fibre or filler, and the cationic starch is used in an amount of from 8 to 10% by weight, based on the dry weight of the filler.
Claim 40
Dependent Claim
14 words
Loaded paper made by a process as claimed in claims 1, 29 or 33.
References Cited (Backward Citations)
US2949397A
Cited
US2913364A
Cited
US2838397A
Cited
US2943013A
Cited
US3184373A
Cited
US3146157A
Cited
GB1177512A
Cited
US3660338A
Cited
US3563907A
Cited
GB1282551A
Cited
GB1353015A
Cited
US3873336A
Cited
GB1371600A
Cited
GB1429796A
Cited
GB1425114A
Cited
GB1451108A
Cited
GB1505641A
Cited
US4066495A
Cited
GB1527077A
Cited
GB1497280A
Cited
GB1552243A
Cited
US4103080A
Cited
GB1588016A
Cited
US4210490A
Cited
GB1581548A
Cited
GB2001088A
Cited
US4178205A
Cited
US4187142A
Cited
US4189345A
Cited
US4299654A
Cited
US4545854A
Cited
GB2009277A
Cited
GB2016498A
Cited
US4225383A
Cited
EP0003481A2
Cited
DE2817262A1
Cited
US4487657A
Cited
GB2031475A
Cited
EP0011303A2
Cited
EP0020316B1
Cited
US4294885A
Cited
EP0041056A1
Cited
US4405744A
Cited
EP0060291A1
Cited
EP0050316A1
Cited
US4445970A
Cited
GB2125838A
Cited
US4439496A
Cited
EP0080986A2
Cited
EP0100370A1
Cited
EP0132132A2
Cited
US4675245A
Cited
WO1985002635A1
Cited
WO1986000100A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-14 | 1993-11-13 | 1994-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-14 | 1997-11-13 | 1998-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-14 | 2001-11-13 | 2002-05-15 | $7700.00 | Window Closed / Lapsed |